Final answer:
To find h(k(z)), insert k(z) into h(z): h(k(z)) = 5(√5z + 1)² - 1. The functions h(z) and k(z) are not inverse functions because h(k(z)) is not equal to z.
Step-by-step explanation:
The student is asking about the composition of two functions, h(z) and k(z), and whether they are inverse functions. The functions are given as h(z) = 5z² - 1 and k(z) = √5z + 1.
To find the value of h(k(z)), one must first apply k(z) and then apply h to the result.
To determine whether the functions are inverses, we check if h(k(z)) = z and k(h(z)) = z for all values in the domain of z ≥ 0.
To find h(k(z)), we replace z in h(z) with k(z):
h(k(z)) = h(√5z + 1)
= 5(√5z + 1)² - 1
= 5(5z + 2√5z + 1) - 1
= 25z + 10√5z + 4.
This is not equal to z, so they are not inverse functions.