Math Problem Statement

Find the derivatives of given functions and evaluate at specific points.

Solution

Let's go through each question in the image step-by-step.


Question 1

Given: h(x)=x+3xh(x) = \sqrt{x} + \frac{3}{x} Find h(x)h'(x).

Solution:

To differentiate, we need to find the derivatives of each term separately.

  1. Rewrite h(x)h(x): h(x)=x1/2+3x1h(x) = x^{1/2} + 3x^{-1}

  2. Differentiate each term:

    • The derivative of x1/2x^{1/2} is 12x1/2\frac{1}{2}x^{-1/2}.
    • The derivative of 3x13x^{-1} is 3x2-3x^{-2}.
  3. Combine: h(x)=12x1/23x2h'(x) = \frac{1}{2}x^{-1/2} - 3x^{-2} Which can also be written as: h(x)=12x3x2h'(x) = \frac{1}{2\sqrt{x}} - \frac{3}{x^2}


Question 2

Given: f(x)=x+2x31f(x) = \frac{x + 2}{x^3 - 1} Find f(x)f'(x).

Solution:

This is a quotient, so we use the quotient rule: if f(x)=uvf(x) = \frac{u}{v}, then f(x)=uvuvv2f'(x) = \frac{u'v - uv'}{v^2}.

  1. Define uu and vv:

    • u=x+2u = x + 2 and u=1u' = 1
    • v=x31v = x^3 - 1 and v=3x2v' = 3x^2
  2. Apply the quotient rule: f(x)=(1)(x31)(x+2)(3x2)(x31)2f'(x) = \frac{(1)(x^3 - 1) - (x + 2)(3x^2)}{(x^3 - 1)^2}

  3. Simplify: f(x)=x313x36x2(x31)2=2x36x21(x31)2f'(x) = \frac{x^3 - 1 - 3x^3 - 6x^2}{(x^3 - 1)^2} = \frac{-2x^3 - 6x^2 - 1}{(x^3 - 1)^2}


Question 3

Given f(x)=5x3+2x2+6x+12f(x) = 5x^3 + 2x^2 + 6x + 12, find f(x)f'(x).

Solution:

Differentiate term-by-term.

  1. The derivative of 5x35x^3 is 15x215x^2.
  2. The derivative of 2x22x^2 is 4x4x.
  3. The derivative of 6x6x is 66.
  4. The derivative of 1212 is 00.

Combine these to get: f(x)=15x2+4x+6f'(x) = 15x^2 + 4x + 6


Question 4

Given f(x)=3x4+2x3x+2f(x) = 3x^4 + 2x^3 - x + 2, find f(1)f'(1).

Solution:

  1. Differentiate term-by-term:

    • The derivative of 3x43x^4 is 12x312x^3.
    • The derivative of 2x32x^3 is 6x26x^2.
    • The derivative of x-x is 1-1.
    • The derivative of 22 is 00.

    So, f(x)=12x3+6x21f'(x) = 12x^3 + 6x^2 - 1

  2. Substitute x=1x = 1 to find f(1)f'(1): f(1)=12(1)3+6(1)21=12+61=17f'(1) = 12(1)^3 + 6(1)^2 - 1 = 12 + 6 - 1 = 17


Summary of Answers:

  1. h(x)=12x3x2h'(x) = \frac{1}{2\sqrt{x}} - \frac{3}{x^2}
  2. f(x)=2x36x21(x31)2f'(x) = \frac{-2x^3 - 6x^2 - 1}{(x^3 - 1)^2}
  3. f(x)=15x2+4x+6f'(x) = 15x^2 + 4x + 6
  4. f(1)=17f'(1) = 17

Would you like further details or have any questions?


Related Questions

  1. How can the chain rule be applied to composite functions in differentiation?
  2. How does the product rule differ from the quotient rule, and when should each be used?
  3. What is the geometric interpretation of a derivative at a point on a curve?
  4. How can higher-order derivatives provide information about the shape of a graph?
  5. How do you determine points of inflection using the second derivative?

Tip

Remember that simplifying expressions after applying differentiation rules can help in verifying the correctness of your answer.

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Math Problem Analysis

Mathematical Concepts

Differentiation
Quotient Rule
Power Rule

Formulas

Quotient Rule: (u/v)' = (u'v - uv') / v^2
Power Rule: (x^n)' = n*x^(n-1)

Theorems

Quotient Rule
Power Rule

Suitable Grade Level

Grades 10-12