Home
Class 11
MATHS
Find the derivative of the following : ...

Find the derivative of the following :
`x^(3)sinx+2xcosx-2xsinx`

Text Solution

AI Generated Solution

The correct Answer is:
To find the derivative of the function \( f(x) = x^3 \sin x + 2x \cos x - 2x \sin x \), we will differentiate each term separately using the product rule and sum the results. ### Step-by-step Solution: 1. **Identify the function**: \[ f(x) = x^3 \sin x + 2x \cos x - 2x \sin x \] 2. **Differentiate the first term \( x^3 \sin x \)**: - Use the product rule: If \( u = x^3 \) and \( v = \sin x \), then \[ \frac{d}{dx}(uv) = u'v + uv' \] - Calculate \( u' = \frac{d}{dx}(x^3) = 3x^2 \) and \( v' = \frac{d}{dx}(\sin x) = \cos x \). - Applying the product rule: \[ \frac{d}{dx}(x^3 \sin x) = (3x^2)(\sin x) + (x^3)(\cos x) = 3x^2 \sin x + x^3 \cos x \] 3. **Differentiate the second term \( 2x \cos x \)**: - Again, use the product rule: Let \( u = 2x \) and \( v = \cos x \). - Calculate \( u' = \frac{d}{dx}(2x) = 2 \) and \( v' = \frac{d}{dx}(\cos x) = -\sin x \). - Applying the product rule: \[ \frac{d}{dx}(2x \cos x) = (2)(\cos x) + (2x)(-\sin x) = 2 \cos x - 2x \sin x \] 4. **Differentiate the third term \( -2x \sin x \)**: - Use the product rule: Let \( u = -2x \) and \( v = \sin x \). - Calculate \( u' = \frac{d}{dx}(-2x) = -2 \) and \( v' = \frac{d}{dx}(\sin x) = \cos x \). - Applying the product rule: \[ \frac{d}{dx}(-2x \sin x) = (-2)(\sin x) + (-2x)(\cos x) = -2 \sin x - 2x \cos x \] 5. **Combine all the derivatives**: \[ f'(x) = (3x^2 \sin x + x^3 \cos x) + (2 \cos x - 2x \sin x) + (-2 \sin x - 2x \cos x) \] 6. **Simplify the expression**: - Combine like terms: \[ f'(x) = x^3 \cos x + 3x^2 \sin x + 2 \cos x - 2x \sin x - 2 \sin x - 2x \cos x \] - Rearranging gives: \[ f'(x) = x^3 \cos x + (3x^2 - 2x - 2) \sin x + (2 - 2x) \cos x \] ### Final Answer: \[ f'(x) = x^3 \cos x + (3x^2 - 2x - 2) \sin x + (2 - 2x) \cos x \]
Promotional Banner

Topper's Solved these Questions

  • LIMITS AND DERIVATIVES

    MODERN PUBLICATION|Exercise EXERCISE 13 (a)|57 Videos
  • LIMITS AND DERIVATIVES

    MODERN PUBLICATION|Exercise EXERCISE 13 (b)|59 Videos
  • LIMITS AND DERIVATIVES

    MODERN PUBLICATION|Exercise ILLUSTRATIVE EXAMPLES|16 Videos
  • INTRODUCTION TO THREE DIMENSIONAL GEOMETRY

    MODERN PUBLICATION|Exercise CHAPTER TEST|12 Videos
  • LINEAR INEQUATIONS

    MODERN PUBLICATION|Exercise CHAPTER TEST|12 Videos

Similar Questions

Explore conceptually related problems

Find the derivatives of the following : x^(3)+sinx

Find the derivatives of the following : (x^(2)+2)cosx

Use delta method to find the derivatives of the following : xsinx

Find the derivative of the 7^^x^2+3x

Find the second derivatives of the following functions : xcosx

Find the derivative of x^( -3/2 )

Find the derivatives of the following (1-3) functions : y=x^(2)

Find the derivative of the following functions: (ax^(2)+sinx)(p+qcosx)

Find the derivatives of the following : f(x)=(3x+2)/((x+5)(2x+1)+3)

Find the derivatives of the following : g(x)=(3x^(2)-2)/(x^(2)+7)