What is the derivative of inverse tangent of 2x?

2 Answers
Apr 14, 2015

dy/(dx)=2/(1+4x^2)

Solution
Let

y=tan^(-1)2x

tany=2x

Differentiating both side with respect to 'x'

d/dx(tany)=d/dx(2x)

=>sec^2y(dy/(dx))=2

=>dy/(dx)=2/(sec^2y)

=>dy/(dx)=2/(1+tan^2y)

Now, as
tany=2x

tan^2y=(2x)^2

tan^2y=4x^2

So,

=>dy/(dx)=2/(1+4x^2)

Apr 14, 2015

dy/(dx)=2/(1+4x^2)#

Solution

Let

y=tan^(-1)2x

Differentiating both side with respect to 'x'

dy/dx=d/dx(tan^(-1)2x)

dy/dx=1/(1+(2x)^2)d/dx(2x)

dy/dx=1/(1+(2x)^2).2d/dx(x)

dy/dx=1/(1+(2x)^2).2dx/dx

dy/dx=1/(1+(2x)^2).2

dy/(dx)=2/(1+4x^2)