Sin 2x = 2 sinx cosx Cos2x = 2 cos^2 x 1 So, (sin 2x)/(1cos 2x) = 2 sin x cos x /(1 2 cos^2 x 1) = 2 sin x cos x /2 cos^2 x = sin x /cos x = tan x For the second part,we have tanx = sin 2x/(1cos2x) Put x = 675° tan 675° = sin 135°/ 1 coCosine 2X or Cos 2X is also, one such trigonometrical formula, also known as double angle formula, as it has a double angle in it Because of this, it is being driven by the expressions for trigonometric functions of the sum and difference of two numbers (angles) and related expressions Let us start with the cos two thetas or cos 2X or cosine prove that cot x tan 2x1 =sec 2x lia cotx tan2x 1 = cotx * 2tanx/(1tan^2x) 1 = 2/(1 tan^2x) 1 = (2 (1 tan^2x))/(1 tan^2x) = (1 tan^2x)/(1 tan^2x) multiply top and bottom by cos^2x and you have = (cos^2x sin^2x)/(cos^2x sin^2x) = 1/cos2x = sec2x oobleck
Prove That Cos2x 1 Tan 2x 1 Tan 2x Youtube
