Bytelearn - cat image with glassesAI tutor

Welcome to Bytelearn!

Let’s check out your problem:

Evaluate 
(d)/(dx)[arccos(-2x)] at 
x=(1)/(4).
Use an exact expression.

Evaluate ddx[arccos(2x)] \frac{d}{d x}[\arccos (-2 x)] at x=14 x=\frac{1}{4} .\newlineUse an exact expression.

Full solution

Q. Evaluate ddx[arccos(2x)] \frac{d}{d x}[\arccos (-2 x)] at x=14 x=\frac{1}{4} .\newlineUse an exact expression.
  1. Find derivative of f(x)f(x): step_1: Find the derivative of f(x)=arccos(2x)f(x) = \text{arccos}(-2x). The derivative of arccos(x)\text{arccos}(x) is 11x2-\frac{1}{\sqrt{1-x^2}}, so by the chain rule, the derivative of arccos(2x)\text{arccos}(-2x) is 11(2x)2ddx(2x)-\frac{1}{\sqrt{1-(-2x)^2}} \cdot \frac{d}{dx}(-2x). f(x)=11(2x)2(2)=214x2f'(x) = -\frac{1}{\sqrt{1-(-2x)^2}} \cdot (-2) = \frac{2}{\sqrt{1-4x^2}}.
  2. Evaluate at x=14x = \frac{1}{4}: step_2: Evaluate the derivative at x=14x = \frac{1}{4}.f(14)=214(14)2=211=20f'(\frac{1}{4}) = \frac{2}{\sqrt{1-4*(\frac{1}{4})^2}} = \frac{2}{\sqrt{1-1}} = \frac{2}{\sqrt{0}}.

More problems from Find derivatives of inverse trigonometric functions