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Help for proving trigo identities?
Having some problems as there are few kinds of formula to substitute in.. Like cot^2 x = cosec^2 x -1, cot^2 x =1/tan x, cot^2 x = cos x / tanx and so on for other identities.
i do not know when to use a particular fomula while doing a question.. So any ideas other than practising?
3 Answers
- ErikaLv 44 years ago
utilising the expression for the adaptation of two squares: sin^4 ? - cos^4 ? = (sin^2 ? + cos^2 ?)(sin^2 ? - cos^2 ?) and because sin^2 ? + cos^2 ? = a million, the rest is easy. tan²? - sin²?=sin²?(a million/cos²? - a million), then use sec^2 = a million+tan^2 good success !
