Question

Angles x and y are located in the first quadrant such that sinx=3/5 and cosy=5/13.

a) Determine an exact value for cosx
b) Determine an exact value for siny

Answer 1

a)
let x = the x length
let y = the y length
let r = the length from the origin to the x,y point.

r^2 = x2 + y^2

sine of x = y/r
so y and r are given in the problem.
solve for x.
cosine of x = x/r

Answer 2

In the explanation, the angle x and the x length are different items.