Math Problem Statement

Determine the second derivative of h(x) =xsin(x). Give the answer in the simplest form

Solution

To determine the second derivative of h(x)=xsin(x)h(x) = x\sin(x), we first need to find the first derivative h(x)h'(x) and then the second derivative h(x)h''(x).

Step 1: Find the First Derivative

Using the product rule, which states (uv)=uv+uv(uv)' = u'v + uv', we can differentiate h(x)=xsin(x)h(x) = x\sin(x).

Let u=xu = x and v=sin(x)v = \sin(x).

Then, u=1u' = 1 v=cos(x)v' = \cos(x)

So, h(x)=uv+uv=1sin(x)+xcos(x)h'(x) = u'v + uv' = 1 \cdot \sin(x) + x \cdot \cos(x) h(x)=sin(x)+xcos(x)h'(x) = \sin(x) + x\cos(x)

Step 2: Find the Second Derivative

Now, we differentiate h(x)=sin(x)+xcos(x)h'(x) = \sin(x) + x\cos(x) to find h(x)h''(x).

Using the product rule again on xcos(x)x\cos(x), (xcos(x))=xcos(x)+x(cos(x))\left( x\cos(x) \right)' = x' \cos(x) + x \left( \cos(x) \right)' =1cos(x)+x(sin(x))= 1 \cdot \cos(x) + x \left( -\sin(x) \right) =cos(x)xsin(x)= \cos(x) - x\sin(x)

So, h(x)=(sin(x)+xcos(x))h''(x) = \left( \sin(x) + x\cos(x) \right)' =(sin(x))+(xcos(x))= \left( \sin(x) \right)' + \left( x\cos(x) \right)' =cos(x)+(cos(x)xsin(x))= \cos(x) + \left( \cos(x) - x\sin(x) \right) =cos(x)+cos(x)xsin(x)= \cos(x) + \cos(x) - x\sin(x) =2cos(x)xsin(x)= 2\cos(x) - x\sin(x)

Therefore, the second derivative of h(x)=xsin(x)h(x) = x\sin(x) is: h(x)=2cos(x)xsin(x)h''(x) = 2\cos(x) - x\sin(x)

Would you like more details or have any questions?

Here are 5 questions you might ask:

  1. How do you apply the product rule for derivatives?
  2. Can you explain the chain rule for derivatives?
  3. How do you find the derivative of a trigonometric function?
  4. What are common mistakes to avoid when differentiating products of functions?
  5. Can you show an example of finding a second derivative for a different function?

Tip: Always carefully apply the product and chain rules when differentiating products or compositions of functions.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Calculus
Differentiation
Product Rule
Trigonometric Functions

Formulas

Product rule for differentiation
Derivatives of trigonometric functions

Theorems

-

Suitable Grade Level

Advanced High School