Can someone please help me right now and explain how you did it?! (please don’t put a link)

Find the slope of the line passing through a pair of points

At the beginning of year 1, carlos invests $600 at an annual compound interest rate of 4%. he makes no deposits to or withdrawals from the account. which explicit formula can be used to find the account's balance at the beginning of year 5? what is, the balance?

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