JEE Main · Mathematics · Inverse Trigonometric Functions
If ^ -1 ((3)/(x))+ ^ -1 ((4)/(x))=(π)/(2) , then x is equal to
If sin−1(x3)+sin−1(x4)=2π, then x is equal to
Options
A3
B5
C7
D11
Correct answer
B. 5
Step-by-step solution
Given that,
sin−1(x3)+sin−1(x4)=2π∴sin−1(x3)=2π−sin−1(x4)⇒sin−1(x3)=cos−1(x4)⇒sin−1(x3)=sin−1(xx2−16)⇒x3=xx2−16⇒9=x2−16⇒x2=25⇒x=±5⇒x=5
(∵−5 is not satisfied the given equation)