Question

hello friends cos2 theta ka formula kya hota h

Answer 1

there are 4 formula cos 2x =cos^2x-sin^2x
cos 2x = 1-2sin^2x
cos2x=2cos^2x-1
cos2x=(1-tan^2x)/(1+tan^2x)

Answer 2

$We \: \: know, \: cos \theta = \frac{base}{hypotenuse}$




Square on both sides,



$\cos ^{2} ( \theta) = \frac{ {base}^{2} }{ {hypotenuse}^{2} }$







Other Formula(s),


• cos²A = 1 - sin²A


• cos²A = sin²A / tan²A


• cos²A = sin²A × cot²A