math
posted by Anonymous .
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

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