Question

Can someone please help me with this?
Let f(x)=2x^2+x-3 and g(x)=x-1. Perform the indicated operation, then find the domain.
(f-g)(x)
a. x^2-4; domain: positive real numbers
b. 2x^2-4; domain: all real numbers
c. x^2-4; domain: all real numbers
d. 2x^2; domain: all real numbers

Answer 1

This looks complicated but it is very logical. Unless I am missing something

Just take f(x) - g(x) f(x)=2x^2+x-3 - g(x)=x-1

(f-g)(x) = 2x^2+x-3 - x-1
= 2x^2- 4

You can figure out the domain.

Answer 2

The domain is all real numbers.
Thank you very much that was super helpful. @retirEEd

Answer 3

If you don't mind... It is now asking me to use the same equation but perform it with the equation (f g)(x)
@retirEEd

Answer 4

I think you would set it up like this:
(f g)(x) = 2x^2+x-3 x-1 (multiplying them)

Answer 5

Yes, but show multiplicaion of f and g as (fg)(x) or (f*g)(x).