Question

First find f+g, f-g, fg and Then determine the domain for each function f(x)-4x-2, g(x) = x + 9

Answer 1

The functions are f(x)-4x-2, g(x) = x + 9

1)

f + g  =  (4x - 2) + (x + 9)

f + g  =  5x + 7

Domain : (-infinity, infinity)

2)

f - g =  (4x - 2) - (x + 9) 

f - g =  4x - 2 - x - 9 

f - g =  3x - 11

Domain : (-infinity, infinity)

3)

f g =  (4x - 2) X (x + 9) 

f g  =  4x^2 + 36x - 2x - 18

​f g  =  4x^2 + 34x - 18

Domain : (-infinity, infinity)

Answer :

1)   f + g  =  5x + 7

     Domain : (-infinity, infinity)

2)  f - g =  3x - 11

     Domain : (-infinity, infinity)

3)   ​f g  =  4x^2 + 34x - 18

     Domain : (-infinity, infinity)