Math Problem Statement

Find the derivative of h(z) = (z^3 - z^2 + 4z)(z - 6) using the Product Rule. Then verify by expanding the product.

Solution

To find the derivative of the function h(z)=(z3z2+4z)(z6)h(z) = (z^3 - z^2 + 4z)(z - 6) using the Product Rule, we apply the following formula:

ddz[f(z)g(z)]=f(z)g(z)+f(z)g(z)\frac{d}{dz}[f(z)g(z)] = f'(z)g(z) + f(z)g'(z)

Here:

  • f(z)=z3z2+4zf(z) = z^3 - z^2 + 4z
  • g(z)=z6g(z) = z - 6

Step 1: Compute f(z)f'(z) and g(z)g'(z)

  • f(z)=3z22z+4f'(z) = 3z^2 - 2z + 4
  • g(z)=1g'(z) = 1 (since the derivative of zz is 1 and the derivative of 6-6 is 0)

Step 2: Apply the Product Rule

h(z)=f(z)g(z)+f(z)g(z)h'(z) = f'(z)g(z) + f(z)g'(z)

Substitute the expressions for f(z)f(z), g(z)g(z), f(z)f'(z), and g(z)g'(z):

h(z)=(3z22z+4)(z6)+(z3z2+4z)(1)h'(z) = (3z^2 - 2z + 4)(z - 6) + (z^3 - z^2 + 4z)(1)

Step 3: Simplify

Now, expand the terms: (3z22z+4)(z6)=3z318z22z2+12z+4z24=3z320z2+16z24(3z^2 - 2z + 4)(z - 6) = 3z^3 - 18z^2 - 2z^2 + 12z + 4z - 24 = 3z^3 - 20z^2 + 16z - 24 (z3z2+4z)(1)=z3z2+4z(z^3 - z^2 + 4z)(1) = z^3 - z^2 + 4z

Now, sum the two results: h(z)=(3z320z2+16z24)+(z3z2+4z)h'(z) = (3z^3 - 20z^2 + 16z - 24) + (z^3 - z^2 + 4z) h(z)=4z321z2+20z24h'(z) = 4z^3 - 21z^2 + 20z - 24

Conclusion:

The correct option is D, which matches the expanded form: h(z)=(z6)(3z22z+4)+(z3z2+4z)h'(z) = (z - 6)(3z^2 - 2z + 4) + (z^3 - z^2 + 4z)

Do you need more details, or any further explanation?


Here are 5 related questions for practice:

  1. What is the derivative of h(z)=(z4z3)(z+5)h(z) = (z^4 - z^3)(z + 5) using the product rule?
  2. How do you apply the product rule when there are more than two functions being multiplied?
  3. What happens when one of the functions in a product rule is a constant?
  4. Can you derive h(z)=(ez)(sinz)h(z) = (e^z)(\sin z) using the product rule?
  5. How can you verify a derivative by expanding the original product first?

Tip: Always simplify after applying the product rule to make it easier to combine terms.

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Math Problem Analysis

Mathematical Concepts

Calculus
Product Rule
Derivatives

Formulas

Product Rule: (f(z)g(z))' = f'(z)g(z) + f(z)g'(z)
Derivative of power functions: d/dz[z^n] = nz^(n-1)

Theorems

Product Rule in Differential Calculus

Suitable Grade Level

Grades 11-12 or Introductory College Calculus