Find (f*h)(7)

Question

Let f(x)= x-1, h(x)= -x+1

find (f*h)(7)

Answer 1

Hi Georgina,

 

If f(x)=x+1 and h(x)=-x+1 then the composite function f*h =-x+1+1=-x+2 an when x=7 the composite is equal to -7+2=-5. 

 

I'm assuming the notation f*h is equivalent to f(h(x)) and not f(x) times h(x).

 

Regards

Jim

Answer 2

f(x)= x-1, h(x)= -x+1

 

(f*h)(7) = (f(7))*(h(7)) = 6*(-6) = -36

Answer 3

 f(X) = X -1

 

  h(X) = - X +1

 

  ( f * h ) ( X ) = ( X - 1 ) ( - X + 1 )

                     

                     =  - X^2 + X + X -1

                    =   - X ^2 + 2X - 1

 

    ( f * h) ( 7 ) =   - 7^2 + 2( 7 ) - 1

 

                      =  - 49 + 14 - 1 = - 36