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# Help! Algebra Question involving trig!! watch

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1. Im stuck on this question which is really annoyin cos i can normally do this sort of question and would appreciate it if anyone can solve it:

Show that 4cos2x/(sin2x)^2 is identitically equal to (cosecx)^2 - (secx)^2

It is on a P3 test so please do not use anything above this level othawise I will not understand!! Also if u use ne otha identities please could u quote them in the solution so i will be able to follow it through.

Thanx to anyone who can help me out.
2. (Original post by the_anomaly)
Show that 4cos2x/(sin2x)^2 is identitically equal to (cosecx)^2 - (secx)^2
(cosecx)^2 - (secx)^2 = 1/(sinx)^2 - 1/(cosx)^2
= [(cosx)^2 - (sinx)^2 ] : (sinxcosx)^2
= cos2x / [(sin2x)/2]^2
= cos2x / 0.25(sinx2x)^2
= 4cos2x/(sin2x)^2.
That's all.

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