Get Answers to all your Questions

header-bg qa

Need solution for RD Sharma Maths Class 12 Chapter 3 Inverse Trigonometric Functions Excercise Fill in the Blanks Question 11

Answers (1)

Answer:

                \pi+\tan^{-1}\left ( \frac{x+y}{1-xy} \right )

Hint:

You must know the values of inverse trigonometric function.

Given:

x> 0,y> 0,xy> 1, then find \tan^{-1}x+\tan^{-1}y

Solution:

Using inverse trigonometry rule,

                \tan^{-1}x+\tan^{-1}y=\tan^{-1}\left ( \frac{x+y}{1-xy} \right ),xy> 1

                \tan^{-1}x=a\Rightarrow x=\tan a
                \tan^{-1}y=b\Rightarrow y=\tan b

 \Rightarrow         0< a+b< \pi,\tan\left ( a+b \right )< 0

                \frac{\pi}{2}< a+b< \pi

                \frac{-\pi}{2}< a+b-\pi< 0

\Rightarrow         \tan\left ( a+b-\pi \right )=-\tan\left [ \pi-\left ( a+b \right ) \right ]

\Rightarrow         \tan\left ( a+b \right )=\left ( \frac{x+y}{1-xy} \right )

\Rightarrow         \tan^{-1}\left ( \frac{x+y}{1-xy} \right )=a+b -\pi

\Rightarrow         a+b= \pi+\tan^{-1}\left ( \frac{x+y}{1-xy} \right )

\Rightarrow         \tan^{-1}x+\tan^{-1}y= \pi+\tan^{-1}\left ( \frac{x+y}{1-xy} \right )

Posted by

infoexpert27

View full answer

Crack CUET with india's "Best Teachers"

  • HD Video Lectures
  • Unlimited Mock Tests
  • Faculty Support
cuet_ads