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Homework Statement
Simplify AND Solve for X
cos2xsinx=1
Homework Equations
The triples, doubles
The Attempt at a Solution
cos2xsinx=1
(cos^2x-sin^2x)(sinx)=1
(-1x)(sinx)=1
-sinx=1
sinx= -1
?
..
:-/
Help.. :)
Graph cos(2x) and sin(x) on [0,2pi]. Or do this cos^2(x)-sin^2(x)=1-2*sin^2(x). So you have (1-2*sin^2(x))*sin(x)=1. If sin(x)=u then you have (1-2*u^2)*u=1. That's a cubic equation for u. Can you find the real root?I have no idea may i have another clue