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# C3 Trigonometry help watch

1. Hi so I'm finding this question difficult,

Prove that:
cosec(2x) - cot (2x) = tan x

any help is appreciated, thanks
Hi so I'm finding this question difficult,

Prove that:
cosec(2x) - cot (2x) = tan x

any help is appreciated, thanks
What have you tried?
3. (Original post by RDKGames)
What have you tried?
so I have tried changing cosec (2x) into 1/sin(2x) and cot(2x) into cos(2x)/sin(2x)

Im not sure if i have to use the double angle formula or if its even needed :/
so I have tried changing cosec (2x) into 1/sin(2x) and cot(2x) into cos(2x)/sin(2x)

Im not sure if i have to use the double angle formula or if its even needed :/
Yes you got it right. You can combine the two fractions too as they have the same denominator. Use double angle formulae and express 1 as and things should cancel down nicely.
5. (Original post by RDKGames)
Yes you got it right. You can combine the two fractions too as they have the same denominator. Use double angle formulae and express 1 as and things should cancel down nicely.
so which formula for cos(2x) should i use? and for the denominator I got 2sin (x)cos (x)
so which formula for cos(2x) should i use? and for the denominator I got 2sin (x)cos (x)
Preferably the one which involves both sine and cosine in order to cancel with the 1. Yeah the denominator is correct.
7. (Original post by RDKGames)
Preferably the one which involves both sine and cosine in order to cancel with the 1. Yeah the denominator is correct.
Ahh thanks so much!

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