Mister Exam

Derivative of cos^7(x)

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

The graph:

from to

Piecewise:

The solution

You have entered [src]
   7   
cos (x)
cos7(x)\cos^{7}{\left(x \right)}
d /   7   \
--\cos (x)/
dx         
ddxcos7(x)\frac{d}{d x} \cos^{7}{\left(x \right)}
Detail solution
  1. Let u=cos(x)u = \cos{\left(x \right)}.

  2. Apply the power rule: u7u^{7} goes to 7u67 u^{6}

  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:

    7sin(x)cos6(x)- 7 \sin{\left(x \right)} \cos^{6}{\left(x \right)}


The answer is:

7sin(x)cos6(x)- 7 \sin{\left(x \right)} \cos^{6}{\left(x \right)}

The graph
02468-8-6-4-2-10105-5
The first derivative [src]
      6          
-7*cos (x)*sin(x)
7sin(x)cos6(x)- 7 \sin{\left(x \right)} \cos^{6}{\left(x \right)}
The second derivative [src]
     5    /     2           2   \
7*cos (x)*\- cos (x) + 6*sin (x)/
7(6sin2(x)cos2(x))cos5(x)7 \cdot \left(6 \sin^{2}{\left(x \right)} - \cos^{2}{\left(x \right)}\right) \cos^{5}{\left(x \right)}
The third derivative [src]
     4    /        2            2   \       
7*cos (x)*\- 30*sin (x) + 19*cos (x)/*sin(x)
7(30sin2(x)+19cos2(x))sin(x)cos4(x)7 \left(- 30 \sin^{2}{\left(x \right)} + 19 \cos^{2}{\left(x \right)}\right) \sin{\left(x \right)} \cos^{4}{\left(x \right)}
The graph
Derivative of cos^7(x)