CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Solve for x

Cos​​​​-1[(x​​​​​​2​​​-1)/(x​​​2+1)] + Tan​-1[2x/(x​​​​​​2​​​​​-1)] = 2π/3

​​​​​​

Open in App
Solution

Here , cos-1 ( x2 – 1 / x2 + 1) + tan-1( 2x/ x2 – 1) = 2π/3
LHS = cos-1 ( x2 – 1 / x2 + 1) + tan-1( 2x/ x2 – 1)
Dividing throughout by x2 ,
cos-1 ( 1 – (1/x2) /( 1 + ( 1/x2) ) + tan-1( 2/x / 1 – (1/x2) )
= cos-1( 1 - (1/x)2 / 1 + (1/x)2 ) + tan-1 ( 2 (1/x) / 1 – (1/x)2 )
=2tan-1(1/x) + 2tan-1(1/x) [ using 2tan-1x = cos-1( 1 – x2 / 1 + x2 ) = tan-1( 2x / 1 – x2) ]
=4tan-1(1/x)
RHS = 2 π/3
So 4 tan-1( 1/x ) = 2 π/3
Or tan-1(1/x) = π/6
Or 1/x = 1/√3
Or x = √3

flag
Suggest Corrections
thumbs-up
3
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Even and Odd Extension
MATHEMATICS
Watch in App
Join BYJU'S Learning Program
CrossIcon