Given f(x)=4x^2-9 and g(x)=2x+3 find each value

Question

Given f(x)=4x^2-9 and g(x)=2x+3 find each value

FIND EACH VALUE

1. (f+g)(x)
2. (f-g)(x)
3. (fg)(x)
4. f(g(3))
5. g(f(3))

Answer 1

To do (f+g)(x) simply add the two functions together and combine like terms where possible. You would do a similar thing for questions 2 and 3 except you would subtract the two functions for question 2 and multiply the two functions together for question 3.

For question 4, you would start with the inside function, in this case g(3). Wherever you see an "x" on the right side of the g(x) equation, replace it with a 3 and solve. Once you find out what number g(3) is equal to, then you take that number and plug it into the f(x) function and solve.

You would use the same procedure for question 5 as in question 4 except you would start with f(3) instead of g(3).