Math Problem Statement

Find the difference quotient f(x+h) - f(x) / h for f(x) = 5x^2 - 3 and simplify.

Solution

The problem asks to find and simplify the difference quotient for the function f(x)=5x23f(x) = 5x^2 - 3. The difference quotient formula is given by:

f(x+h)f(x)h,where h0.\frac{f(x+h) - f(x)}{h}, \quad \text{where } h \neq 0.

Steps to solve:

  1. Find f(x+h)f(x+h): f(x+h)=5(x+h)23f(x+h) = 5(x+h)^2 - 3 Expanding (x+h)2(x+h)^2: f(x+h)=5(x2+2xh+h2)3=5x2+10xh+5h23f(x+h) = 5(x^2 + 2xh + h^2) - 3 = 5x^2 + 10xh + 5h^2 - 3

  2. Substitute f(x+h)f(x+h) and f(x)f(x) into the difference quotient: f(x+h)f(x)h=(5x2+10xh+5h23)(5x23)h\frac{f(x+h) - f(x)}{h} = \frac{(5x^2 + 10xh + 5h^2 - 3) - (5x^2 - 3)}{h} Simplify the expression: =5x2+10xh+5h235x2+3h= \frac{5x^2 + 10xh + 5h^2 - 3 - 5x^2 + 3}{h} =10xh+5h2h= \frac{10xh + 5h^2}{h}

  3. Simplify the quotient: Factor hh from the numerator: =h(10x+5h)h= \frac{h(10x + 5h)}{h} Since h0h \neq 0, cancel hh from the numerator and denominator: =10x+5h= 10x + 5h

Thus, the simplified form of the difference quotient is:

10x+5h10x + 5h

Would you like further clarification or more details?

Here are 5 related questions to explore further:

  1. How does the difference quotient relate to the derivative of a function?
  2. What happens to the difference quotient as h0h \to 0?
  3. Can you apply the difference quotient to a linear function, like f(x)=3x+2f(x) = 3x + 2?
  4. How does expanding (x+h)2(x + h)^2 work for higher degree polynomials?
  5. Why is it important that h0h \neq 0 in the difference quotient?

Tip: The difference quotient is a foundational concept in calculus and leads directly to the definition of a derivative!

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Math Problem Analysis

Mathematical Concepts

Difference Quotient
Quadratic Functions

Formulas

f(x+h) - f(x) / h
f(x) = 5x^2 - 3
Expanding (x + h)^2

Theorems

Difference Quotient Formula

Suitable Grade Level

Grades 9-12