We know from double angle formula that
These identities can also be used to reduce angles
Half angle formulas (Power reducing formulas)
Last updated at Dec. 16, 2024 by Teachoo
Last updated at Dec. 16, 2024 by Teachoo
We know from double angle formula that sin 2x = 2 sin x cos x = 2 tan x / (1 + tan^2 x) cos 2x = cos^2 x - sin^2 x = 1 - 2 sin^2 x = 2 cos^2 x - 1 = 1 - tan^2 x / 1 + tan^2 x tan 2x = 2 tan x / (1 - tan^2 x) These identities can also be used to reduce angles sin x = 2 sin x/2 cos x/2 = 2 tan x/2 / (1 + tan^2 x/2) cos x = cos^2 x/2 - sin^2 x/2 = 1 - 2 sin^2 x/2 = 2 cos^2 x/2 - 1 = 1 - tan^2 x/2 / 1 + tan^2 x/2 tan x = 2 tan x/2 / (1 - tan^2 x/2)
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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo