Exam 8: Combinations of Functions Composite Functions

arrow
  • Select Tags
search iconSearch Question
  • Select Tags

Determine whether the statement is true or false. ​ If f(x)= x + 1 and g(x)= 5x,then (fg)(x)=(gf)(x)( f \circ g ) ( x ) = ( g \circ f ) ( x ) . ​

Free
(Multiple Choice)
4.9/5
(42)
Correct Answer:
Verified

A

Let f (x)= 2x + 1,g(x)= 3x - 2.Find the function.​ (fg)(x)( f - g ) ( x )

Free
(Multiple Choice)
5.0/5
(36)
Correct Answer:
Verified

B

The spread of a contaminant is increasing in a circular pattern on the surface of a lake.The radius of the contaminant can be modeled by r(t)=2.25tr ( t ) = 2.25 \sqrt { t } ,where r is the radius in meters and t is the time in hours since contamination. ​ Find a function that gives the area A of the circular lake in terms of the time since the spread began. ​

Free
(Multiple Choice)
4.8/5
(29)
Correct Answer:
Verified

E

The weekly cost C of producing units x in a manufacturing process is given by C(x)=30x+750C ( x ) = 30 x + 750 .The number of units x produced in t hours is given by x(t)=70tx ( t ) = 70 t . ​ Find the cost of the units produced in 6 hours. ​

(Multiple Choice)
4.8/5
(31)

Find ( f − g )(x).​ f(x)=6x7x6g(x)=4xf ( x ) = - \frac { 6 x } { 7 x - 6 } \quad g ( x ) = - \frac { 4 } { x }

(Multiple Choice)
4.8/5
(32)

​Find gfg \circ f .​ f(x)=x2,g(x)=x4f ( x ) = x ^ { 2 } , g ( x ) = x - 4 ​ ​

(Multiple Choice)
4.8/5
(41)

Let f (x)= 3x,g (x)= x + 1.Find the composite function. ​​ (fg)(x)( f \circ g ) ( x ) ​ Please give the respnce as an expression (not an equation).

(Short Answer)
4.8/5
(30)

The total numbers of Navy personnel N (in thousands)and Marines personnel M (in thousands)from 2000 through 2007 can be approximated by the models​ N(t)=0.194t37.88t2+12.9t+375N ( t ) = 0.194 t ^ { 3 } - 7.88 t ^ { 2 } + 12.9 t + 375 and M(t)=0.031t30.25t2+6.7t+173M ( t ) = 0.031 t ^ { 3 } - 0.25 t ^ { 2 } + 6.7 t + 173 ​ where t represents the year,with t = 0 corresponding to 2000. Find and interpret (NM)(t)( N - M ) ( t ) . ​

(Multiple Choice)
4.9/5
(31)

Find fgf \circ g and the domain of the composite function.​ f(x)=x,g(x)=x+3f ( x ) = | x | , g ( x ) = x + 3

(Multiple Choice)
4.9/5
(33)

Find gfg \circ f and the domain of the composite function.​ f(x)=x2+4,g(x)=xf ( x ) = x ^ { 2 } + 4 , g ( x ) = \sqrt { x }

(Multiple Choice)
4.7/5
(30)

​Evaluate the indicated function for f(x)=x2+5f ( x ) = x ^ { 2 } + 5 and g(x)=x2g ( x ) = x - 2 .​ (fg)(5)( f g ) ( 5 ) ​ ​

(Multiple Choice)
4.9/5
(41)

The number of people playing tennis T (in millions)in the United States from 2000 through 2007 can be approximated by the function​ T(t)=0.0236t40.3401t3+6.556t22.86t+26.8T ( t ) = 0.0236 t ^ { 4 } - 0.3401 t ^ { 3 } + 6.556 t ^ { 2 } - 2.86 t + 26.8 ​ and the U.S.population P (in millions)from 2000 through 2007 can be approximated by the function P(t)=5.78t+221.5P ( t ) = 5.78 t + 221.5 ,where t represents the year,with t = 0 corresponding to 2000. Find h(t)=T(t)P(t)h ( t ) = \frac { T ( t ) } { P ( t ) } . ​

(Multiple Choice)
4.8/5
(30)

The monthly cost C of running the machinery in a factory for t hours is given by​ C(t)=40t+400C ( t ) = 40 t + 400 The number of hours t needed to produce x products is given by t(x)=6xt ( x ) = 6 x . Find the equation representing the cost C of manufacturing x products.

(Multiple Choice)
4.9/5
(29)

Evaluate the indicated function for f(x)=x26f ( x ) = x ^ { 2 } - 6 and g(x)=x+4g ( x ) = x + 4 . ( fg )(1)

(Multiple Choice)
4.8/5
(43)

Find (fg)(x)( f g ) ( x ) .​ f(x)=1x2,g(x)=1x4f ( x ) = \frac { 1 } { x ^ { 2 } } , g ( x ) = \frac { 1 } { x ^ { 4 } }

(Multiple Choice)
4.8/5
(39)

The number N of bacteria in a refrigerated food is given by N(T)=10T220T+600,1T20N ( T ) = 10 T ^ { 2 } - 20 T + 600,1 \leq T \leq 20 where T is the temperature of the food in degrees Celsius.When the food is removed from refrigeration,the temperature of the food is given by T(t)=3t+2,0t6T ( t ) = 3 t + 2,0 \leq t \leq 6 where t is the time in hours. Find the bacteria count after 0.5 hour. ​

(Multiple Choice)
4.9/5
(24)

Find (f/g)(x)( f / g ) ( x ) .​ f(x)=1x2,g(x)=1x4f ( x ) = \frac { 1 } { x ^ { 2 } } , g ( x ) = \frac { 1 } { x ^ { 4 } }

(Multiple Choice)
4.9/5
(32)

Find fgf \circ g . f(x)=2x9g(x)=x+5f ( x ) = - 2 x - 9 \quad g ( x ) = x + 5

(Multiple Choice)
4.8/5
(38)

Let f (x)= x2 - 1,g (x)= 3x - 2.Find the value of the function.​ (f+g)(5)( f + g ) ( 5 )

(Short Answer)
4.9/5
(30)

Evaluate the indicated function for f(x)=x2+3f ( x ) = x ^ { 2 } + 3 and g(x)=x4g ( x ) = x - 4 .​ (fg)(3t)( f - g ) ( 3 t ) ​ ​

(Multiple Choice)
4.7/5
(30)
Showing 1 - 20 of 58
close modal

Filters

  • Essay(0)
  • Multiple Choice(0)
  • Short Answer(0)
  • True False(0)
  • Matching(0)