Get Answers to all your Questions

header-bg qa

Please solve rd sharma class 12 chapter inverse trigonometric functions exercise 3.2 question 4 sub question (ii) maths textbook solution

Answers (1)

best_answer

Answer: \frac{3\pi }{4}

Hint: The range of the principal value branch of  \cos ^{-1} is \left [ 0,\pi \right ]

Given:    \cos ^{-1}\left ( \frac{-1}{\sqrt{2}} \right )

Solution:

Let \cos ^{-1}\left ( \frac{-1}{\sqrt{2}} \right ) =y

                    \cos y=\left ( \frac{-1}{\sqrt{2}} \right )

                            y=-\cos \frac{\pi }{4}

                                =\cos \left ( \pi -\frac{\pi }{4} \right )

                                =\cos \left ( \frac{3\pi }{4} \right )

                            y=\frac{3\pi }{4}

Therefore, the principal value of \cos ^{-1}\left ( \frac{-1}{\sqrt{2}} \right ) is \frac{3\pi }{4}.

 

 

Posted by

infoexpert26

View full answer

Crack CUET with india's "Best Teachers"

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