What is the derivative of f (x) = 3 arcsin (x^4)?

1 Answer
Jul 9, 2016

f'(x)=(12x^3)/{sqrt(1-x^8)}.

Explanation:

Let y=f(x)=3arcsinx^4.

We know that d/dt(arcsint)=1/sqrt(1-t^2).

Let, y=3arcsint, where, t=x^4. Thus, y becomes a fun. of t, and, t of x.

Therefore, by Chain Rule, dy/dx=dy/dt*dt/dx.

=d/dt(3arcsint)*d/dx(x^4),

=3*d/dt(arcsint)*4*x^(4-1),
=12*1/sqrt(1-t^2)*x^3,
=(12x^3)/[sqrt{1-(x^4)^2)},
:. f'(x)=(12x^3)/{sqrt(1-x^8)}.

Enjoy Maths.!