Math Problem Statement

If f(x) = x^2 - 2x + 3, evaluate the difference quotient (f(a + h) - f(a)) / h

Solution

The image shows the following problem:

You are asked to evaluate the difference quotient for the function f(x)=x22x+3f(x) = x^2 - 2x + 3. The difference quotient is given by:

f(a+h)f(a)h\frac{f(a + h) - f(a)}{h}

Let's solve this step by step:

  1. Find f(a+h)f(a + h): f(a+h)=(a+h)22(a+h)+3f(a + h) = (a + h)^2 - 2(a + h) + 3 Expanding this: (a+h)2=a2+2ah+h2(a + h)^2 = a^2 + 2ah + h^2 2(a+h)=2a2h-2(a + h) = -2a - 2h Thus, f(a+h)=a2+2ah+h22a2h+3f(a + h) = a^2 + 2ah + h^2 - 2a - 2h + 3

  2. Find f(a)f(a): f(a)=a22a+3f(a) = a^2 - 2a + 3

  3. Compute f(a+h)f(a)f(a + h) - f(a): f(a+h)f(a)=(a2+2ah+h22a2h+3)(a22a+3)f(a + h) - f(a) = \left(a^2 + 2ah + h^2 - 2a - 2h + 3\right) - \left(a^2 - 2a + 3\right) Simplifying this expression: f(a+h)f(a)=2ah+h22hf(a + h) - f(a) = 2ah + h^2 - 2h

  4. Divide by hh: f(a+h)f(a)h=2ah+h22hh\frac{f(a + h) - f(a)}{h} = \frac{2ah + h^2 - 2h}{h} Factor out hh in the numerator: f(a+h)f(a)h=h(2a+h2)h\frac{f(a + h) - f(a)}{h} = \frac{h(2a + h - 2)}{h} Cancel hh (as long as h0h \neq 0): f(a+h)f(a)h=2a+h2\frac{f(a + h) - f(a)}{h} = 2a + h - 2

So, the difference quotient for the function f(x)=x22x+3f(x) = x^2 - 2x + 3 is:

2a+h22a + h - 2

Would you like further details or clarifications? Here are 5 related questions that can expand your understanding:

  1. How would you evaluate the limit of the difference quotient as h0h \to 0?
  2. What does the difference quotient represent in calculus?
  3. How would the result change if the function were cubic instead of quadratic?
  4. Can you compute the derivative of the function using this result?
  5. How does the difference quotient relate to the slope of a secant line?

Tip: The difference quotient is the foundation of the derivative. As h0h \to 0, the difference quotient gives the slope of the tangent line to the curve at x=ax = a.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Difference Quotient
Quadratic Functions
Algebra

Formulas

Difference quotient: (f(a + h) - f(a)) / h

Theorems

Basic Differentiation Rules

Suitable Grade Level

High School (Grades 10-12)