Question 1165389
1)-csc^2(x)= 2/(cos2(x)-1)

2)cos2(x)=(1-tan^2(x))/(1+tan^2(x))

3)sin2(x)-2cot(x)sin^2(x)=0
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Not clear.
1)-csc^2(x)= 2/(cos2(x)-1)

Is it -csc^2(x)= 2/(cos(2x)-1) ?
Or -csc^2(x)= 2/(cos^2(x)-1) ?