Mister Exam

Derivative of cosx^3

Function f() - derivative -N order at the point
v

The graph:

from to

Piecewise:

The solution

You have entered [src]
   3   
cos (x)
cos3(x)\cos^{3}{\left(x \right)}
d /   3   \
--\cos (x)/
dx         
ddxcos3(x)\frac{d}{d x} \cos^{3}{\left(x \right)}
Detail solution
  1. Let u=cos(x)u = \cos{\left(x \right)}.

  2. Apply the power rule: u3u^{3} goes to 3u23 u^{2}

  3. Then, apply the chain rule. Multiply by ddxcos(x)\frac{d}{d x} \cos{\left(x \right)}:

    1. The derivative of cosine is negative sine:

      ddxcos(x)=sin(x)\frac{d}{d x} \cos{\left(x \right)} = - \sin{\left(x \right)}

    The result of the chain rule is:

    3sin(x)cos2(x)- 3 \sin{\left(x \right)} \cos^{2}{\left(x \right)}


The answer is:

3sin(x)cos2(x)- 3 \sin{\left(x \right)} \cos^{2}{\left(x \right)}

The graph
02468-8-6-4-2-10102.5-2.5
The first derivative [src]
      2          
-3*cos (x)*sin(x)
3sin(x)cos2(x)- 3 \sin{\left(x \right)} \cos^{2}{\left(x \right)}
The second derivative [src]
  /     2           2   \       
3*\- cos (x) + 2*sin (x)/*cos(x)
3(2sin2(x)cos2(x))cos(x)3 \cdot \left(2 \sin^{2}{\left(x \right)} - \cos^{2}{\left(x \right)}\right) \cos{\left(x \right)}
The third derivative [src]
  /       2           2   \       
3*\- 2*sin (x) + 7*cos (x)/*sin(x)
3(2sin2(x)+7cos2(x))sin(x)3 \left(- 2 \sin^{2}{\left(x \right)} + 7 \cos^{2}{\left(x \right)}\right) \sin{\left(x \right)}
The graph
Derivative of cosx^3