SOLUTION: if sin x= 4/5, where 0<x<90, find the value of cos(x+180).

Algebra ->  Trigonometry-basics -> SOLUTION: if sin x= 4/5, where 0<x<90, find the value of cos(x+180).      Log On


   

Question 138906: if sin x= 4/5, where 0
Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
There is a 3,4,5 right triangle in quadrant I. The opposite is 4 and the hypotenuse is 5. sin=opp/hyp
Add 90 deg. and it is in quadrant III.
Cos=adj/hyp=-3/5
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Ed