Find the distance between the following points (8 , -5) and (2, 13)

Alicia puts $400 in a bank account. each year the account earns 5% simple interest. how much money will be in her bank account in six months?

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).

What is the greatest number of parts of a circle that can be formed by cutting the circle with 7 straight cuts? (note: the parts do not have to be equal in size)