Function question

Question

The function m(n) is defined by . Which of the following is the value of m(m(n))?

A. -n⁹

B. -n⁶

C. n³

D. n⁶

E. n⁹

I thought I had functions down pat, but this makes no sense to me. Even the given explanation confused me. Any suggestions?

Answer 1

m(n) = -n³

To evaluate m(m(n)), just substitute m(n) for n in the expression for m(n).

m(m(n)) = -[m(n)]³ = -(-n³)³ = -(-1)³n⁹ = -(-1)n⁹ = n⁹

Answer (E) is correct.