Mister Exam

Derivative of lnsin(ax)+cos(ax)

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

The graph:

from to

Piecewise:

The solution

You have entered [src]
log(sin(a*x)) + cos(a*x)
$$\log{\left(\sin{\left(a x \right)} \right)} + \cos{\left(a x \right)}$$
d                           
--(log(sin(a*x)) + cos(a*x))
dx                          
$$\frac{\partial}{\partial x} \left(\log{\left(\sin{\left(a x \right)} \right)} + \cos{\left(a x \right)}\right)$$
Detail solution
  1. Differentiate term by term:

    1. Let .

    2. The derivative of is .

    3. Then, apply the chain rule. Multiply by :

      1. Let .

      2. The derivative of sine is cosine:

      3. Then, apply the chain rule. Multiply by :

        1. The derivative of a constant times a function is the constant times the derivative of the function.

          1. Apply the power rule: goes to

          So, the result is:

        The result of the chain rule is:

      The result of the chain rule is:

    4. Let .

    5. The derivative of cosine is negative sine:

    6. Then, apply the chain rule. Multiply by :

      1. The derivative of a constant times a function is the constant times the derivative of the function.

        1. Apply the power rule: goes to

        So, the result is:

      The result of the chain rule is:

    The result is:

  2. Now simplify:


The answer is:

The first derivative [src]
              a*cos(a*x)
-a*sin(a*x) + ----------
               sin(a*x) 
$$- a \sin{\left(a x \right)} + \frac{a \cos{\left(a x \right)}}{\sin{\left(a x \right)}}$$
The second derivative [src]
    /       2                \
  2 |    cos (a*x)           |
-a *|1 + --------- + cos(a*x)|
    |       2                |
    \    sin (a*x)           /
$$- a^{2} \left(\cos{\left(a x \right)} + 1 + \frac{\cos^{2}{\left(a x \right)}}{\sin^{2}{\left(a x \right)}}\right)$$
The third derivative [src]
   /     3                             \
 3 |2*cos (a*x)   2*cos(a*x)           |
a *|----------- + ---------- + sin(a*x)|
   |    3          sin(a*x)            |
   \ sin (a*x)                         /
$$a^{3} \left(\sin{\left(a x \right)} + \frac{2 \cos{\left(a x \right)}}{\sin{\left(a x \right)}} + \frac{2 \cos^{3}{\left(a x \right)}}{\sin^{3}{\left(a x \right)}}\right)$$