Math Problem Statement

Use the four-step process to find f'(x) and then find f'(1), f'(2), and f'(3) for the function f(x) = x^2 + 3x - 2.

Solution

The question asks to use the four-step process to find the derivative f(x)f'(x) of the function f(x)=x2+3x2f(x) = x^2 + 3x - 2 and then to find f(1)f'(1), f(2)f'(2), and f(3)f'(3).

The four-step process for finding the derivative is:

  1. Step 1: Find f(x+h)f(x + h), where f(x)=x2+3x2f(x) = x^2 + 3x - 2.

  2. Step 2: Compute the difference f(x+h)f(x)f(x + h) - f(x).

  3. Step 3: Divide the difference by hh, i.e., find f(x+h)f(x)h\frac{f(x + h) - f(x)}{h}.

  4. Step 4: Take the limit as h0h \to 0 of the expression from Step 3 to get f(x)f'(x).

Let's apply this step by step.

Step 1: Find f(x+h)f(x + h)

f(x+h)=(x+h)2+3(x+h)2f(x + h) = (x + h)^2 + 3(x + h) - 2 Expanding the terms: f(x+h)=(x2+2xh+h2)+(3x+3h)2f(x + h) = (x^2 + 2xh + h^2) + (3x + 3h) - 2 f(x+h)=x2+2xh+h2+3x+3h2f(x + h) = x^2 + 2xh + h^2 + 3x + 3h - 2

Step 2: Compute f(x+h)f(x)f(x + h) - f(x)

Now, subtract f(x)=x2+3x2f(x) = x^2 + 3x - 2 from f(x+h)f(x + h): f(x+h)f(x)=(x2+2xh+h2+3x+3h2)(x2+3x2)f(x + h) - f(x) = (x^2 + 2xh + h^2 + 3x + 3h - 2) - (x^2 + 3x - 2) Simplifying: f(x+h)f(x)=2xh+h2+3hf(x + h) - f(x) = 2xh + h^2 + 3h

Step 3: Divide by hh

Now, divide the expression by hh: f(x+h)f(x)h=2xh+h2+3hh\frac{f(x + h) - f(x)}{h} = \frac{2xh + h^2 + 3h}{h} Simplifying: f(x+h)f(x)h=2x+h+3\frac{f(x + h) - f(x)}{h} = 2x + h + 3

Step 4: Take the limit as h0h \to 0

Now, take the limit as h0h \to 0: f(x)=limh0(2x+h+3)=2x+3f'(x) = \lim_{h \to 0} (2x + h + 3) = 2x + 3

Thus, the derivative f(x)=2x+3f'(x) = 2x + 3.

Now, find f(1)f'(1), f(2)f'(2), and f(3)f'(3):

  • f(1)=2(1)+3=2+3=5f'(1) = 2(1) + 3 = 2 + 3 = 5
  • f(2)=2(2)+3=4+3=7f'(2) = 2(2) + 3 = 4 + 3 = 7
  • f(3)=2(3)+3=6+3=9f'(3) = 2(3) + 3 = 6 + 3 = 9

Final Answers:

  • f(1)=5f'(1) = 5
  • f(2)=7f'(2) = 7
  • f(3)=9f'(3) = 9

Would you like more details on any of the steps or have any further questions?


Here are five related questions to explore further:

  1. How would the four-step process change for a function with a higher degree, like f(x)=x3+2x2xf(x) = x^3 + 2x^2 - x?
  2. How is the four-step process related to the definition of a derivative in calculus?
  3. What would the second derivative f(x)f''(x) be for this function?
  4. How would the derivative change if the constant term was removed from the function?
  5. What happens if you evaluate the derivative at negative values of xx, like f(1)f'(-1)?

Tip: The four-step process is a formal way to derive the derivative using the definition of limits, but you can often take shortcuts using known derivative rules.

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Math Problem Analysis

Mathematical Concepts

Derivatives
Limits
Polynomials

Formulas

f'(x) = lim_{h \to 0} \frac{f(x+h) - f(x)}{h}
Power rule for differentiation

Theorems

Limit Definition of a Derivative

Suitable Grade Level

Grades 10-12 (High School Calculus)