Question

Given cosx=-4/5 and x is in Quadrant3, find sinx

Answer 1

if x is in Q3, sinx<0

Answer 2

draw a triangle, that is all

Answer 3

draw a triangle
\[\rm sin \rm \theta = \frac{ opposite }{ hypotenuse }~~~~ \cos \theta = \frac{ adjacent }{ hypotenuse } ~~\tan \theta = \frac{ opposite }{ adjacent }\]

cos =adjacent /hyp