કાર્ય અને સંબંધો (Functions and Relations)

Table of Contents

અંકશાસ્ત્ર અને ગણિતમાં “કાર્ય” અને “સંબંધ” બંનેના ઉપયોગ સાથે ખૂબ જ મહત્વપૂર્ણ ગણિતીય ધોરણો છે.

1.1 કાર્યની વ્યાખ્યા (Definition of a Function)

કાર્ય એ એક ગણિતીય સિદ્ધાંત છે, જેમાં દરેક ઇનપુટ (ડોમેઇનના તત્વો) ને ચોક્કસપણે અનન્ય આઉટપુટ (રેન્જના તત્વો) સાથે જોડવામાં આવે છે. સાદું કહ્યું તો, દરેક ઇનપુટને એક અનન્ય આઉટપુટ મળે છે.

y=f(x) અહીં x ઇનપુટ છે અને f(x) આઉટપુટ છે.

1.2 કાર્યના પ્રકારો (Types of Functions)

1.2.1 લિનિયર કાર્ય (Linear Function)

લિનિયર કાર્ય એ તે કાર્ય છે, જેમાં કાર્યના મૂલ્યો એક સીધી રેખા દ્વારા દર્શાવવામાં આવે છે.

f(x)=mx+b

અહીં m ઢાળ છે અને bIntercept છે.

Example 1:

લિનિયર કાર્ય f(x)=2x+3 માટે વિવિધ મૂલ્યો શોધો.

Solution:

For x=1:

f(x)=2(1)+3

=2+3

=5

For x=2:

f(x)=2(2)+3

=4+3

=1

For x=3:

f(x)=2(3)+3

=6+3

=9

1.2.2 ક્વાડ્રેટીક કાર્ય (Quadratic Function)

ક્વાડ્રેટીક કાર્ય એ તે કાર્ય છે, જેમાં ઇનપુટ ત્રિજ્યા (square) દ્વારા દર્શાવેલું હોય છે.

f(x)=ax2+bx+c

અહીં a, b, અને c સમાંક છે.

Example 2:

ક્વાડ્રેટીક કાર્ય f(x)=x24x+3 માટે ઇનપુટના મૂલ્યો શોધો.

Solution:

For x=2:

f(x)=(2)24(2)+3

=48+3

=1

For x=1:

f(x)=(1)24(1)+3

=1+4+3

=8

1.2.3 ક્યુબિક કાર્ય (Cubic Function)

ક્યુબિક કાર્ય એ તે છે, જ્યાં ઇનપુટનો ઘન (cube) કરવામાં આવે છે.

f(x)=ax3+bx2+cx+d

અહીં a, b, c, અને d સ્થિર સમાંક છે.

Example 3:

ક્યુબિક કાર્ય f(x)=x32x2+x+1 માટે આઉટપુટ શોધો.

Solution:

For x=1:

f(x)=(1)32(1)2+1+1

=12+1+1

=1

For x=2:

f(x)=(2)32(2)2+(2)+1

=882+1

=17

1.2.4 અથંકાર્ય (Exponential Function)

અથંકાર્ય એ તે કાર્ય છે જ્યાં ઇનપુટનું સ્તરે (power) ઉત્પન્ન થાય છે.

f(x)=ax

Example 4:

અથંકાર્ય f(x)=2x માટે ઇનપુટના મૂલ્યો શોધો.

Solution:

For x=3:

f(x)=23

=8

For x=1:

f(x)=21

=12


1.3 સંબંધ (Relations)

સંબંધ એ ડોમેઇન અને રેન્જ વચ્ચેના જોડાણને દર્શાવે છે, જ્યાં દરેક ઇનપુટનો એક કે વધુ આઉટપુટ હોઈ શકે છે.


1.4 Example Continuation for Functions and Relations

Example 5:

Evaluate the quadratic function f(x)=3x22x+1 for given values of x.

Solution:

For x=2:

f(x)=3(2)22(2)+1

=3(4)4+1

=124+1

=9

For x=1:

f(x)=3(1)22(1)+1

=3(1)+2+1

=6


Example 6:

Evaluate the cubic function f(x)=x33x2+2x5.

Solution:

For x=1:

f(x)=(1)33(1)2+2(1)5

=13+25

=5

For x=2:

f(x)=(2)33(2)2+2(2)5

=81245

=29


Example 7:

Evaluate the exponential function f(x)=3x.

Solution:

For x=4:

f(x)=34

=81

For x=2:

f(x)=32

=132

=19


Example 8:

Solve for f(x)=2x+3 and g(x)=x24.

Find f(2) and g(3).

Solution:

For f(2):

f(x)=2(2)+3

=4+3

=7

For g(3):

g(x)=(3)24

=94

=5


Example 9:

Consider the linear function f(x)=4x+1. Evaluate for x=2 and x=5.

Solution:

For x=2:

f(x)=4(2)+1

=8+1

=9

For x=5:

f(x)=4(5)+1

=20+1

=19


Example 10:

Evaluate the quadratic function f(x)=x24x+6 for x=3 and x=1.

Solution:

For x=3:

f(x)=(3)24(3)+6

=912+6

=3

For x=1:

f(x)=(1)24(1)+6

=1+4+6

=11


Example 11:

Solve for f(x)=5x7 and evaluate at x=4 and x=3.

Solution:

For x=4:

f(x)=5(4)7

=207

=13

For x=3:

f(x)=5(3)7

=157

=22


Example 12:

Evaluate the function f(x)=x2+5x8 for x=2 and x=4.

Solution:

For x=2:

f(x)=(2)2+5(2)8

=4+108

=6

For x=4:

f(x)=(4)2+5(4)8

=16208

=12


Example 13:

Evaluate the cubic function f(x)=x3+2x24x+1 for x=1 and x=2.

Solution:

For x=1:

f(x)=(1)3+2(1)24(1)+1

=1+24+1

=0

For x=2:

f(x)=(2)3+2(2)24(2)+1

=8+8+8+1

=9


Example 14:

Evaluate the function f(x)=3x27x+2 for x=5 and x=3.

Solution:

For x=5:

f(x)=3(5)27(5)+2

=7535+2

=42

For x=3:

f(x)=3(3)27(3)+2

=27+21+2

=50


Example 15:

Evaluate the quadratic function f(x)=x2+2x5 for x=4 and x=2.

Solution:

For x=4:

f(x)=(4)2+2(4)5

=16+85

=19

For x=2:

f(x)=(2)2+2(2)5

=445

=5


Example 16:

Evaluate the linear function f(x)=3x+7 for x=3 and x=1.

Solution:

For x=3:

f(x)=3(3)+7

=9+7

=2

For x=1:

f(x)=3(1)+7

=3+7

=10


Example 17:

Evaluate the cubic function f(x)=2x3x2+4x1 for x=2 and x=3.

Solution:

For x=2:

f(x)=2(2)3(2)2+4(2)1

=2(8)4+81

=164+81

=19

For x=3:

f(x)=2(3)3(3)2+4(3)1

=2(27)9121

=549121

=76


Example 18:

Solve for f(x)=x26x+9 and evaluate for x=5 and x=2.

Solution:

For x=5:

f(x)=(5)26(5)+9

=2530+9

=4

For x=2:

f(x)=(2)26(2)+9

=4+12+9

=25


Example 19:

Evaluate the function f(x)=3x2+2x1 for x=1 and x=3.

Solution:

For x=1:

f(x)=3(1)2+2(1)1

=3+21

=4

For x=3:

f(x)=3(3)2+2(3)1

=3(9)61

=2761

=20


Example 20:

Evaluate the quadratic function f(x)=4x25x+6 for x=2 and x=4.

Solution:

For x=2:

f(x)=4(2)25(2)+6

=4(4)10+6

=1610+6

=12

For x=4:

f(x)=4(4)25(4)+6

=4(16)+20+6

=64+20+6

=90


Example 21:

Evaluate the linear function f(x)=2x+4 for x=0 and x=5.

Solution:

For x=0:

f(x)=2(0)+4

=0+4

=4

For x=5:

f(x)=2(5)+4

=10+4

=6


Example 22:

Evaluate the cubic function f(x)=x32x2+x4 for x=3 and x=1.

Solution:

For x=3:

f(x)=(3)32(3)2+34

=2718+34

=8

For x=1:

f(x)=(1)32(1)2+(1)4

=1214

=8


Example 23:

Evaluate the quadratic function f(x)=2x24x+1 for x=4 and x=2.

Solution:

For x=4:

f(x)=2(4)24(4)+1

=2(16)16+1

=3216+1

=17

For x=2:

f(x)=2(2)24(2)+1

=2(4)+8+1

=8+8+1

=17


Example 24:

Evaluate the function f(x)=5x23x+2 for x=2 and x=3.

Solution:

For x=2:

f(x)=5(2)23(2)+2

=5(4)6+2

=206+2

=16

For x=3:

f(x)=5(3)23(3)+2

=5(9)+9+2

=45+9+2

=56


Example 25:

Solve the linear function f(x)=4x7 for x=3 and x=5.

Solution:

For x=3:

f(x)=4(3)7

=127

=5

For x=5:

f(x)=4(5)7

=207

=27


Example 26:

Evaluate the quadratic function f(x)=x2+3x7 for x=5 and x=4.

Solution:

For x=5:

f(x)=(5)2+3(5)7

=25+157

=33

For x=4:

f(x)=(4)2+3(4)7

=16127

=3


Example 27:

Solve for f(x)=6x2 and evaluate for x=4 and x=3.

Solution:

For x=4:

f(x)=6(4)2

=242

=22

For x=3:

f(x)=6(3)2

=182

=20


Example 28:

Evaluate the function f(x)=2x3x2+5x1 for x=3 and x=2.

Solution:

For x=3:

f(x)=2(3)3(3)2+5(3)1

=2(27)9+151

=549+151

=59

For x=2:

f(x)=2(2)3(2)2+5(2)1

=2(8)4101

=164101

=31


Example 29:

Evaluate the quadratic function f(x)=4x26x+2 for x=2 and x=3.

Solution:

For x=2:

f(x)=4(2)26(2)+2

=4(4)12+2

=1612+2

=6

For x=3:

f(x)=4(3)26(3)+2

=4(9)+18+2

=36+18+2

=56


Example 30:

Evaluate the linear function f(x)=3x+5 for x=6 and x=1.

Solution:

For x=6:

f(x)=3(6)+5

=18+5

=13

For x=1:

f(x)=3(1)+5

=3+5

=8


Example 31:

Solve for f(x)=2x2+3x4 and evaluate for x=1 and x=5.

Solution:

For x=1:

f(x)=2(1)2+3(1)4

=2+34

=1

For x=5:

f(x)=2(5)2+3(5)4

=2(25)154

=50154

=31


Example 32:

Evaluate the cubic function f(x)=x34x+7 for x=4 and x=2.

Solution:

For x=4:

f(x)=(4)34(4)+7

=6416+7

=55

For x=2:

f(x)=(2)34(2)+7

=8+8+7

=7


Example 33:

Evaluate the quadratic function f(x)=5x23x+8 for x=2 and x=4.

Solution:

For x=2:

f(x)=5(2)23(2)+8

=5(4)6+8

=206+8

=22

For x=4:

f(x)=5(4)23(4)+8

=5(16)+12+8

=80+12+8

=100


Example 34:

Evaluate the linear function f(x)=5x+9 for x=7 and x=3.

Solution:

For x=7:

f(x)=5(7)+9

=35+9

=26

For x=3:

f(x)=5(3)+9

=15+9

=24


Example 35:

Solve for f(x)=x2+4x6 and evaluate for x=5 and x=4.

Solution:

For x=5:

f(x)=(5)2+4(5)6

=25+206

=39

For x=4:

f(x)=(4)2+4(4)6

=16166

=6


Example 36:

Evaluate the function f(x)=3x32x2+4x9 for x=3 and x=2.

Solution:

For x=3:

f(x)=3(3)32(3)2+4(3)9

=3(27)2(9)+129

=8118+129

=66

For x=2:

f(x)=3(2)32(2)2+4(2)9

=3(8)2(4)89

=24889

=49


Example 37:

Evaluate the quadratic function f(x)=2x23x+5 for x=1 and x=6.

Solution:

For x=1:

f(x)=2(1)23(1)+5

=23+5

=4

For x=6:

f(x)=2(6)23(6)+5

=2(36)+18+5

=72+18+5

=95


Example 38:

Solve for f(x)=2x+6 and evaluate for x=4 and x=7.

Solution:

For x=4:

f(x)=2(4)+6

=8+6

=2

For x=7:

f(x)=2(7)+6

=14+6

=20


Example 39:

Evaluate the quadratic function f(x)=x22x+4 for x=3 and x=5.

Solution:

For x=3:

f(x)=(3)22(3)+4

=96+4

=7

For x=5:

f(x)=(5)22(5)+4

=25+10+4

=39


Example 40:

Evaluate the cubic function f(x)=x34x+6 for x=2 and x=3.

Solution:

For x=2:

f(x)=(2)34(2)+6

=88+6

=6

For x=3:

f(x)=(3)34(3)+6

=27+12+6

=9


Example 41:

Solve for f(x)=3x2+5x2 and evaluate for x=4 and x=1.

Solution:

For x=4:

f(x)=3(4)2+5(4)2

=3(16)+202

=48+202

=66

For x=1:

f(x)=3(1)2+5(1)2

=3(1)52

=352

=4


Example 42:

Evaluate the linear function f(x)=7x+3 for x=6 and x=2.

Solution:

For x=6:

f(x)=7(6)+3

=42+3

=39

For x=2:

f(x)=7(2)+3

=14+3

=17


Example 43:

Evaluate the quadratic function f(x)=4x26x+8 for x=2 and x=4.

Solution:

For x=2:

f(x)=4(2)26(2)+8

=4(4)12+8

=1612+8

=12

For x=4:

f(x)=4(4)26(4)+8

=4(16)+24+8

=64+24+8

=96


Example 44:

Evaluate the function f(x)=x23x+9 for x=1 and x=5.

Solution:

For x=1:

f(x)=(1)23(1)+9

=13+9

=7

For x=5:

f(x)=(5)23(5)+9

=25+15+9

=49


Example 45:

Evaluate the cubic function f(x)=2x3x2+5x+1 for x=2 and x=1.

Solution:

For x=2:

f(x)=2(2)3(2)2+5(2)+1

=2(8)4+10+1

=164+10+1

=23

For x=1:

f(x)=2(1)3(1)2+5(1)+1

=2(1)15+1

=215+1

=7


Example 46:

Evaluate the quadratic function f(x)=5x23x+2 for x=4 and x=2.

Solution:

For x=4:

f(x)=5(4)23(4)+2

=5(16)12+2

=8012+2

=70

For x=2:

f(x)=5(2)23(2)+2

=5(4)+6+2

=20+6+2

=28


Example 47:

Solve for f(x)=x24x+7 and evaluate for x=2 and x=3.

Solution:

For x=2:

f(x)=(2)24(2)+7

=48+7

=3

For x=3:

f(x)=(3)24(3)+7

=9+12+7

=28


Example 48:

Evaluate the linear function f(x)=2x+5 for x=4 and x=6.

Solution:

For x=4:

f(x)=2(4)+5

=8+5

=3

For x=6:

f(x)=2(6)+5

=12+5

=17


Example 49:

Evaluate the quadratic function f(x)=x2+3x4 for x=5 and x=2.

Solution:

For x=5:

f(x)=(5)2+3(5)4

=25+154

=36

For x=2:

f(x)=(2)2+3(2)4

=464

=6


Example 50:

Evaluate the cubic function f(x)=x3+2x25x+3 for x=3 and x=1.

Solution:

For x=3:

f(x)=(3)3+2(3)25(3)+3

=27+1815+3

=33

For x=1:

f(x)=(1)3+2(1)25(1)+3

=1+2+5+3

=9


Example 51:

Evaluate the quadratic function f(x)=4x23x+6 for x=3 and x=4.

Solution:

For x=3:

f(x)=4(3)23(3)+6

=4(9)9+6

=369+6

=33

For x=4:

f(x)=4(4)23(4)+6

=4(16)+12+6

=64+12+6

=82


Example 52:

Evaluate the cubic function f(x)=x32x2+3x4 for x=2 and x=3.

Solution:

For x=2:

f(x)=(2)32(2)2+3(2)4

=88+64

=2

For x=3:

f(x)=(3)32(3)2+3(3)4

=271894

=58


Example 53:

Evaluate the quadratic function f(x)=2x2+5x3 for x=4 and x=1.

Solution:

For x=4:

f(x)=2(4)2+5(4)3

=2(16)+203

=32+203

=49

For x=1:

f(x)=2(1)2+5(1)3

=2(1)53

=253

=6


Example 54:

Evaluate the linear function f(x)=6x+7 for x=5 and x=3.

Solution:

For x=5:

f(x)=6(5)+7

=30+7

=23

For x=3:

f(x)=6(3)+7

=18+7

=25


Example 55:

Evaluate the quadratic function f(x)=3x24x+5 for x=2 and x=2.

Solution:

For x=2:

f(x)=3(2)24(2)+5

=3(4)8+5

=128+5

=9

For x=2:

f(x)=3(2)24(2)+5

=3(4)+8+5

=12+8+5

=25


Example 56:

Evaluate the cubic function f(x)=2x3+3x24x+6 for x=2 and x=1.

Solution:

For x=2:

f(x)=2(2)3+3(2)24(2)+6

=2(8)+3(4)8+6

=16+128+6

=26

For x=1:

f(x)=2(1)3+3(1)24(1)+6

=2(1)+3(1)+4+6

=2+3+4+6

=11


Example 57:

Solve for f(x)=x25x+7 and evaluate for x=3 and x=2.

Solution:

For x=3:

f(x)=(3)25(3)+7

=915+7

=1

For x=2:

f(x)=(2)25(2)+7

=4+10+7

=21


Example 58:

Evaluate the linear function f(x)=4x6 for x=2 and x=4.

Solution:

For x=2:

f(x)=4(2)6

=86

=2

For x=4:

f(x)=4(4)6

=166

=22


Example 59:

Evaluate the quadratic function f(x)=3x2+4x8 for x=5 and x=1.

Solution:

For x=5:

f(x)=3(5)2+4(5)8

=3(25)+208

=75+208

=87

For x=1:

f(x)=3(1)2+4(1)8

=3(1)48

=348

=9


Example 60:

Evaluate the cubic function f(x)=x32x2+4x3 for x=3 and x=2.

Solution:

For x=3:

f(x)=(3)32(3)2+4(3)3

=2718+123

=18

For x=2:

f(x)=(2)32(2)2+4(2)3

=8883

=27


Example 61:

Evaluate the quadratic function f(x)=5x23x+9 for x=4 and x=3.

Solution:

For x=4:

f(x)=5(4)23(4)+9

=5(16)12+9

=8012+9

=77

For x=3:

f(x)=5(3)23(3)+9

=5(9)+9+9

=45+9+9

=63


Example 62:

Solve for f(x)=2x24x+3 and evaluate for x=1 and x=4.

Solution:

For x=1:

f(x)=2(1)24(1)+3

=24+3

=1

For x=4:

f(x)=2(4)24(4)+3

=2(16)+16+3

=32+16+3

=51


Example 63:

Evaluate the linear function f(x)=7x5 for x=6 and x=2.

Solution:

For x=6:

f(x)=7(6)5

=425

=37

For x=2:

f(x)=7(2)5

=145

=19


Example 64:

Evaluate the quadratic function f(x)=4x23x+2 for x=3 and x=5.

Solution:

For x=3:

f(x)=4(3)23(3)+2

=4(9)9+2

=369+2

=29

For x=5:

f(x)=4(5)23(5)+2

=4(25)+15+2

=100+15+2

=117


Example 65:

Solve for f(x)=2x2+5x4 and evaluate for x=2 and x=3.

Solution:

For x=2:

f(x)=2(2)2+5(2)4

=2(4)+104

=8+104

=14

For x=3:

f(x)=2(3)2+5(3)4

=2(9)154

=18154

=1


Example 66:

Evaluate the function f(x)=3x3+2x24x+5 for x=3 and x=2.

Solution:

For x=3:

f(x)=3(3)3+2(3)24(3)+5

=3(27)+2(9)12+5

=81+1812+5

=92

For x=2:

f(x)=3(2)3+2(2)24(2)+5

=3(8)+2(4)+8+5

=24+8+8+5

=3


Example 67:

Evaluate the quadratic function f(x)=x26x+8 for x=2 and x=4.

Solution:

For x=2:

f(x)=(2)26(2)+8

=412+8

=0

For x=4:

f(x)=(4)26(4)+8

=16+24+8

=48


Example 68:

Evaluate the quadratic function f(x)=5x22x+7 for x=4 and x=3.

Solution:

For x=4:

f(x)=5(4)22(4)+7

=5(16)8+7

=808+7

=79

For x=3:

f(x)=5(3)22(3)+7

=5(9)+6+7

=45+6+7

=58


Example 69:

Evaluate the cubic function f(x)=x3+2x23x+4 for x=2 and x=2.

Solution:

For x=2:

f(x)=(2)3+2(2)23(2)+4

=8+86+4

=14

For x=2:

f(x)=(2)3+2(2)23(2)+4

=8+8+6+4

=10


Example 70:

Solve for f(x)=3x27x+4 and evaluate for x=3 and x=1.

Solution:

For x=3:

f(x)=3(3)27(3)+4

=3(9)21+4

=2721+4

=10

For x=1:

f(x)=3(1)27(1)+4

=3(1)+7+4

=3+7+4

=14


Example 71:

Evaluate the linear function f(x)=4x+5 for x=6 and x=3.

Solution:

For x=6:

f(x)=4(6)+5

=24+5

=19

For x=3:

f(x)=4(3)+5

=12+5

=17


Example 72:

Evaluate the quadratic function f(x)=2x2+3x5 for x=2 and x=4.

Solution:

For x=2:

f(x)=2(2)2+3(2)5

=2(4)+65

=8+65

=9

For x=4:

f(x)=2(4)2+3(4)5

=2(16)125

=32125

=15


Example 73:

Evaluate the cubic function f(x)=x3x2+4x2 for x=3 and x=2.

Solution:

For x=3:

f(x)=(3)3(3)2+4(3)2

=279+122

=28

For x=2:

f(x)=(2)3(2)2+4(2)2

=8482

=22


Example 74:

Solve for f(x)=4x25x+7 and evaluate for x=4 and x=3.

Solution:

For x=4:

f(x)=4(4)25(4)+7

=4(16)20+7

=6420+7

=51

For x=3:

f(x)=4(3)25(3)+7

=4(9)+15+7

=36+15+7

=58


Example 75:

Evaluate the linear function f(x)=3x9 for x=5 and x=2.

Solution:

For x=5:

f(x)=3(5)9

=159

=6

For x=2:

f(x)=3(2)9

=69

=15


Example 76:

Evaluate the quadratic function f(x)=6x24x+5 for x=3 and x=1.

Solution:

For x=3:

f(x)=6(3)24(3)+5

=6(9)12+5

=5412+5

=47

For x=1:

f(x)=6(1)24(1)+5

=6(1)+4+5

=6+4+5

=15


Example 77:

Evaluate the cubic function f(x)=2x33x2+5x7 for x=2 and x=3.

Solution:

For x=2:

f(x)=2(2)33(2)2+5(2)7

=2(8)3(4)+107

=1612+107

=7

For x=3:

f(x)=2(3)33(3)2+5(3)7

=2(27)3(9)157

=5427157

=103


Example 78:

Solve for f(x)=5x2+2x4 and evaluate for x=3 and x=4.

Solution:

For x=3:

f(x)=5(3)2+2(3)4

=5(9)+64

=45+64

=47

For x=4:

f(x)=5(4)2+2(4)4

=5(16)84

=8084

=68


Example 79:

Evaluate the linear function f(x)=5x+6 for x=4 and x=1.

Solution:

For x=4:

f(x)=5(4)+6

=20+6

=14

For x=1:

f(x)=5(1)+6

=5+6

=11


Example 80:

Evaluate the quadratic function f(x)=3x22x+9 for x=1 and x=2.

Solution:

For x=1:

f(x)=3(1)22(1)+9

=3(1)2+9

=32+9

=10

For x=2:

f(x)=3(2)22(2)+9

=3(4)+4+9

=12+4+9

=25


Example 81:

Evaluate the cubic function f(x)=x3+x24x+8 for x=2 and x=3.

Solution:

For x=2:

f(x)=(2)3+(2)24(2)+8

=8+48+8

=12

For x=3:

f(x)=(3)3+(3)24(3)+8

=27+9+12+8

=2


Example 82:

Solve for f(x)=4x2+5x6 and evaluate for x=3 and x=2.

Solution:

For x=3:

f(x)=4(3)2+5(3)6

=4(9)+156

=36+156

=45

For x=2:

f(x)=4(2)2+5(2)6

=4(4)106

=16106

=0


Example 83:

Evaluate the linear function f(x)=6x4 for x=3 and x=5.

Solution:

For x=3:

f(x)=6(3)4

=184

=14

For x=5:

f(x)=6(5)4

=304

=34


Example 84:

Evaluate the quadratic function f(x)=2x24x+7 for x=5 and x=1.

Solution:

For x=5:

f(x)=2(5)24(5)+7

=2(25)20+7

=5020+7

=37

For x=1:

f(x)=2(1)24(1)+7

=2(1)+4+7

=2+4+7

=13


Example 85:

Evaluate the cubic function f(x)=x3x2+6x9 for x=4 and x=3.

Solution:

For x=4:

f(x)=(4)3(4)2+6(4)9

=6416+249

=63

For x=3:

f(x)=(3)3(3)2+6(3)9

=279189

=63


Example 86:

Solve for f(x)=5x26x+3 and evaluate for x=4 and x=2.

Solution:

For x=4:

f(x)=5(4)26(4)+3

=5(16)24+3

=8024+3

=59

For x=2:

f(x)=5(2)26(2)+3

=5(4)+12+3

=20+12+3

=35


Example 87:

Evaluate the linear function f(x)=8x+7 for x=3 and x=5.

Solution:

For x=3:

f(x)=8(3)+7

=24+7

=17

For x=5:

f(x)=8(5)+7

=40+7

=47


Example 88:

Evaluate the quadratic function f(x)=6x22x+9 for x=1 and x=3.

Solution:

For x=1:

f(x)=6(1)22(1)+9

=6(1)2+9

=62+9

=13

For x=3:

f(x)=6(3)22(3)+9

=6(9)+6+9

=54+6+9

=69


Example 89:

Evaluate the cubic function f(x)=3x3+5x27x+4 for x=2 and x=1.

Solution:

For x=2:

f(x)=3(2)3+5(2)27(2)+4

=3(8)+5(4)14+4

=24+2014+4

=34

For x=1:

f(x)=3(1)3+5(1)27(1)+4

=3(1)+5(1)+7+4

=3+5+7+4

=13


Example 90:

Solve for f(x)=4x23x+6 and evaluate for x=4 and x=2.

Solution:

For x=4:

f(x)=4(4)23(4)+6

=4(16)12+6

=6412+6

=58

For x=2:

f(x)=4(2)23(2)+6

=4(4)+6+6

=16+6+6

=28


Example 91:

Evaluate the linear function f(x)=5x3 for x=7 and x=4.

Solution:

For x=7:

f(x)=5(7)3

=353

=32

For x=4:

f(x)=5(4)3

=203

=23


Example 92:

Evaluate the quadratic function f(x)=7x25x+3 for x=2 and x=1.

Solution:

For x=2:

f(x)=7(2)25(2)+3

=7(4)10+3

=2810+3

=21

For x=1:

f(x)=7(1)25(1)+3

=7(1)+5+3

=7+5+3

=15


Example 93:

Evaluate the cubic function f(x)=x33x2+4x6 for x=3 and x=2.

Solution:

For x=3:

f(x)=(3)33(3)2+4(3)6

=2727+126

=6

For x=2:

f(x)=(2)33(2)2+4(2)6

=81286

=34


Example 94:

Solve for f(x)=2x25x+8 and evaluate for x=1 and x=3.

Solution:

For x=1:

f(x)=2(1)25(1)+8

=2(1)5+8

=25+8

=5

For x=3:

f(x)=2(3)25(3)+8

=2(9)+15+8

=18+15+8

=41


Example 95:

Evaluate the linear function f(x)=2x+9 for x=5 and x=6.

Solution:

For x=5:

f(x)=2(5)+9

=10+9

=1

For x=6:

f(x)=2(6)+9

=12+9

=21


Example 96:

Evaluate the quadratic function f(x)=x2+3x+5 for x=3 and x=3.

Solution:

For x=3:

f(x)=(3)2+3(3)+5

=9+9+5

=23

For x=3:

f(x)=(3)2+3(3)+5

=99+5

=5


Example 97:

Evaluate the cubic function f(x)=2x3+4x25x+7 for x=1 and x=2.

Solution:

For x=1:

f(x)=2(1)3+4(1)25(1)+7

=2(1)+4(1)5+7

=2+45+7

=8

For x=2:

f(x)=2(2)3+4(2)25(2)+7

=2(8)+4(4)+10+7

=16+16+10+7

=17


Example 98:

Solve for f(x)=3x26x+8 and evaluate for x=2 and x=3.

Solution:

For x=2:

f(x)=3(2)26(2)+8

=3(4)12+8

=1212+8

=8

For x=3:

f(x)=3(3)26(3)+8

=3(9)+18+8

=27+18+8

=53


Example 99:

Evaluate the linear function f(x)=3x+4 for x=7 and x=4.

Solution:

For x=7:

f(x)=3(7)+4

=21+4

=17

For x=4:

f(x)=3(4)+4

=12+4

=16


Example 100:

Evaluate the quadratic function f(x)=5x27x+10 for x=3 and x=1.

Solution:

For x=3:

f(x)=5(3)27(3)+10

=5(9)21+10

=4521+10

=34

For x=1:

f(x)=5(1)27(1)+10

=5(1)+7+10

=5+7+10

=22

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