Evaluate : ∫ 1/(1+cos3x)dx ​

Question

Evaluate : \(\int\)\(\frac{1}{1+cos3x}\)dx

Answer 1

Let I =\(\int\)\(\frac{1}{1+cos3x}\)dx

= \(\int\)\(\frac{1}{1+cos3x}\)dx

Now,

Multiply with Conjugate,

Hence,

 I =\(\)\(\frac{1-cos3x}{3sin3x}\) + C