SOLUTION: Using double angle formula find the exact value, given sec&#952;=4,3pi/2<&#952;<2pi sin2&#952;= cos2&#952;= tan2&#952;=

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Question 754199: Using double angle formula find the exact value, given secθ=4,3pi/2<θ<2pi
sin2θ=
cos2θ=
tan2θ=

Answer by tommyt3rd(5050) About Me  (Show Source):
You can put this solution on YOUR website!
sec%28theta%29=4,


cos%28theta%29=1%2F4




3pi%2F2%3Ctheta%3C2pi

i.e. we are in quadrant IV

means...

sin%28theta%29=-sqrt%2815%29%2F4



cos2%2Atheta=2cos%5E2%28theta%29-1=2%281%2F4%29-1=-1%2F2


We forgo using tangent identities since we don't need them