If (cos x)y = (tan y)x, prove that 
Here,
Taking log on both sides,
[Using log 
=b log a]
Differentiating it with respect to x using product rule and chain rule,
42
If (cos x)y = (tan y)x, prove that
Here,
Taking log on both sides,
[Using log =b log a]
Differentiating it with respect to x using product rule and chain rule,