+0  
 
0
421
1
avatar

Given that Alpha and Beta are in quadrant 2 and sinA=4/5 and cosB= -15/17 Find: CosA

 Dec 15, 2015
 #1
avatar
0

Sin^2(A) + Cos^2(A)=1

4/5^2 + Cos^2(A)=1

Cos^2(A)=1 - .64=.36 take the sqrt of both sides,

Cos(A)=.6=3/5

 Dec 15, 2015

2 Online Users

avatar