The two acute angles of a right triangle have degree measures of x and y. If #sin#x = #5/13#, what is the value of #cos# y?

2 Answers

#cos y = 5/13#

Explanation:

#x# and #y# are complementary.

#sin x = 5/13 = (opp)/(hyp)#

However, the side opposite (opp) the angle #x# is also the side adjacent (adj) to angle #y#.

#cos y = (adj)/(hyp) = 5/13#

May 18, 2018

# 5/13#.

Explanation:

Clearly, #x+y=90^@#.

#:. y=90^@-x#.

#:. cosy=cos(90^@-x)=sinx=5/13#, as Respected Mr. Hsia

has readily derived!