How do you find the derivative of (arcsin x)^2?

1 Answer
Oct 29, 2016

d/dx(arcsinx)^2 = (2arcsinx)/sqrt(1 - x^2)

Explanation:

Let y = (arcsinx)^2 => y^(1/2) = arcsinx
:. sin(y^(1/2)) = x

Differentiating wrt x;
:. cos(y^(1/2))(1/2y^(-1/2))dy/dx = 1

:. dy/dx = 2/(cos(y^(1/2))(y^(-1/2)))

:. dy/dx = (2y^(1/2))/(cos(y^(1/2)))

Now sin^2A + cos^2A -= 1 => cosA = sqrt(1 - sin^2A
So, cos(y^(1/2)) = sqrt(1 - sin^2(y^(1/2))
:. cos(y^(1/2)) = sqrt(1 - x^2)

Hence, dy/dx = (2arcsinx)/sqrt(1 - x^2)