Please help!! Is this equation linear? Why or why not?

Use composition to determine if (x) or h(x) is the inverse of f(x) for the limited domain x2-1.

Given sin28.4=.4756, cos28.4=.8796, and tan28.4=.5407 find the cos of 61.6

If you invest 1,500 today in a bank that gives you a 5 percent annual interest rate, which of these items can you buy in two years? a. electronics worth $1,650 b. fitness equipment worth $1,700 c. a holiday package worth $2,000