Inverse Trigonometric Functions Question 213

Question: If $ a<\frac{1}{32}, $ then the number of solution of $ {{({{\sin }^{-1}}x)}^{3}}+{{({{\cos }^{-1}}x)}^{3}}=a{{\pi }^{3}} $ is

Options:

A) 0

B) 1

C) 2

D) Infinite

Show Answer

Answer:

Correct Answer: A

Solution:

From previous solution $ \frac{{{\pi }^{3}}}{32}\le {{({{\sin }^{-1}}x)}^{3}}+{{({{\cos }^{-1}}x)}^{3}}\le \frac{7\pi }{8} $

Here $ a<\frac{1}{32} $ .

So, number of solution is zero.