Solve question no 13 Q 13 Prove that : tenx4+12 cos-1ab + tenx4-12cos-1ab=2ba - Maths - Inverse Trigonometric Functions

Question

Solve question no 13

Q 13 Prove that : t e n x 4 + 1 2   cos - 1 a b   +
  t e n x 4 - 1 2 cos - 1 a b = 2 b a

Neha Sethi · Accepted Answer

Dear student
<img alt="" src=
"https://s3mn%20mnimgs%20com/img/shared/content_ck_images/ck_5aabfe313af84%20png">
Identity used:1)tanA±B=tan±tanB1∓tanA tanB2) (A+B)2=A2+B2+2AB3) cos2A=1-tan2A1+tan2A
Regards

Solve question.no.13 Q 13. Prove that : t e n x 4 + 1 2 cos - 1 a b + t e n x 4 - 1 2 cos - 1 a b = 2 b a

Solve question.no.13

Q 13. Prove that : $t e n (\frac{x}{4} + \frac{1}{2} \cos^{- 1} \frac{a}{b}) + t e n (\frac{x}{4} \frac{- 1}{2} \cos^{- 1} \frac{a}{b}) = \frac{2 b}{a}$