2. Point B has coordinates (-12,5) and lies on the circle whose equation is x² + y2 =169. If an angle is drawn in standard position with its terminal ray extending through point B, what is the cosine of the angle?

Whats are the trickiest steps to do when adding or subtracting rational expressions? how does knowledge of rational numbers u in adding and subtracting rational expressions?

What is number 31 as a sum of tens and ones?

Let x have probability generating function gx (s) and let un generating function u(s) of the sequence uo, u1, satisfies p(x > n). show that the (1- s)u(s) = 1 - gx(s), whenever the series defining these generating functions converge.