Question

can anyone tell me reason for 2nd step​

Answer 1

Answer:

Check well bro... there is a formula for that ..

That whole tan is converting into pi by 4...! it's an formula

Answer 2

Answer:

$2( \tan^{ - 1}1- \tan^{ - 1}x) = \tan^{ - 1}x \\ 2\tan^{ - 1}1 - 2\tan^{ - 1}x = \tan^{ - 1}x \\ 2 \times \frac{\pi}{4} = 3\tan^{ - 1}x$

the value of tan^-1(1)=π/4

hope u get this....