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Trig ratios halp! (1 Viewer)

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EDIT: lawl, i typed the first question wrong...

 
Last edited:

life92

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4 cos^2 - 4 sin = 1
4 (1 - sin^2) - 4 sin = 1
4 - 4sin^2 - 4sin = 1
4sin^2 + 4sin -3 = 0
(2sin-1)(2sin+3)=0

therefore, sinx = 1/2, sinx = -3/2
for sin x = 1/2 ,, x = 30, 150

for sinx = -3/2, there are no solutions as -1< sinx <1
 

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