We are given (x) = –4x and g(x) = 5x² The composition of f with g should be done this way: <span>[f o g](x) = f [ g(x) ] = f ( 5x</span>² ) = -4 (5x²) - 20 x²<span />
He squared 4x instead of adding exponents of x and multiplying -4 by 5.
Step-by-step explanation:
When multiplying to exponents with the same base you must add the exponents. Andrew multiplied the two functions and took 4x and squared it to get 4x² which is wrong. The correct solution is: