How do you find the derivative of (sqrt(1-x^2))arcsinx?

1 Answer
Sep 7, 2017

1-(x*arc sinx)/sqrt(1-x^2), |x|<1.

Explanation:

Let, y=sqrt(1-x^2)*arc sinx.

The desired Derivative can be obtained using the Product Rule for

Diffn.

Here is, an another way to solve the Problem.

We subst. t=arc sinx, |x|<=1. rArr sint=x, |t| <=pi/2.

Hence, y=sqrt(1-sin^2t)*t=tcost," where, "t=sinx....(1).

Thus, y" is a fun. of "t," and, t of "x.

By the Chain Rule, then, we have,

dy/dx=dy/dt*dt/dx,

={d/dt(tcost)}{d/dx(arc sinx)}......[because, (1)],

={cost*d/dt(t)+t*d/dt(cost)}(1/sqrt(1-x^2)),

={cost+t(-sint)}cosx,

={sqrt(1-x^2)-x*arc sinx}(1/sqrt(1-x^2)),

rArr dy/dx=1-(x*arc sinx)/sqrt(1-x^2), |x|<1.

N.B. : The Domain of g" is "[-1,1];" and, that of "g'" is "(-1,1).

Enjoy Maths.!