Let f (x) = –5x + 3 and g(x) = 6x – 2. Find f • g and its domain.

Question

–30x^2 + 28x – 6; all real numbers except x = 1/3
–15x2 – 8x – 12; all real numbers except x = 3/5
–30x^2 + 28x – 6; all real numbers
–15x^2 – 8x – 12; all real numbers

Answer 1

To find f • g, we need to multiply the two functions together:

f • g = (-5x + 3)(6x - 2)
= -30x^2 + 28x - 6

The domain of f • g is all real numbers, since there are no restrictions on x in the multiplication of the two functions.