Question

Prove that

cot x – 2cot 2x = tan x

Answer 1

To Prove: cot x – 2cot 2x = tan x

Taking LHS,

= cot x – 2cot 2x …(i)

We know that,

cotx = \(\frac{cosx}{sinx}\)

Replacing x by 2x, we get

cot2x = \(\frac{cos2x}{sin2x}\)

So, eq. (i) becomes

= RHS

∴ LHS = RHS

Hence Proved