# Trigonometry questions

A) Give the vale of :

(i) sin^-1 (cosx ), only acute angle.

(ii) tan (sin^1 x)

(iii) tan [ tan^-1 ( x+ 1)/(x-1) + tan ^-1 (x-1 )/x

b) Solve : cos^-1 x + cos^-1 2x = 60°

c)State what is the most interesting thing learnt in studying Trigonometry and why you have select it to be introduced in your

program of study

https://brainmass.com/math/trigonometry/trigonometry-plan-questions-189007

#### Solution Preview

Hi,

Please find the explanations/solutions.

Plane Trigonometry

Final checks :

a) Give the vale of :

(i) sin^-1 (cosx ), only acute angle.

Solution:

sin^-1 (cosx ) = sin^-1 (sin( - x )) = - x

(ii) tan (sin^-1 x)

Let sin^-1 x = a

sina = x

Then

tan (sin^-1 x) = tan(a) =

(iii) tan [ tan^-1 ( x+ 1)/(x-1) + tan ^-1 (x-1 )/x]

Solution:

b) ...

#### Solution Summary

Step by step solutions to all the problems is provided.

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