Math Problem Statement

Find the difference quotient of f(x) = x^2 + 5.

Solution

The image you've uploaded asks to find the difference quotient of the function f(x)=x2+5f(x) = x^2 + 5. The difference quotient formula is:

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

Let's go through the steps to find the difference quotient.

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

Given f(x)=x2+5f(x) = x^2 + 5, we substitute x+hx+h into the function:

f(x+h)=(x+h)2+5f(x+h) = (x+h)^2 + 5

Expand (x+h)2(x+h)^2:

(x+h)2=x2+2xh+h2(x+h)^2 = x^2 + 2xh + h^2

Thus:

f(x+h)=x2+2xh+h2+5f(x+h) = x^2 + 2xh + h^2 + 5

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

Now, subtract f(x)=x2+5f(x) = x^2 + 5 from f(x+h)f(x+h):

f(x+h)f(x)=(x2+2xh+h2+5)(x2+5)f(x+h) - f(x) = (x^2 + 2xh + h^2 + 5) - (x^2 + 5)

Simplifying:

f(x+h)f(x)=2xh+h2f(x+h) - f(x) = 2xh + h^2

Step 3: Compute the difference quotient

Now, divide the result by hh:

f(x+h)f(x)h=2xh+h2h\frac{f(x+h) - f(x)}{h} = \frac{2xh + h^2}{h}

Simplify the expression:

f(x+h)f(x)h=2x+h\frac{f(x+h) - f(x)}{h} = 2x + h

Thus, the difference quotient is:

2x+h\boxed{2x + h}

Would you like more details on any step? Here are some related questions you might find useful:

  1. What is the difference quotient used for?
  2. How do you find the derivative using the difference quotient?
  3. How does the difference quotient relate to the slope of a secant line?
  4. What happens to the difference quotient as hh approaches zero?
  5. Can you use the difference quotient for functions other than polynomials?

Tip: The difference quotient is a critical concept in calculus, as it leads directly to the definition of the derivative!

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Math Problem Analysis

Mathematical Concepts

Algebra
Functions
Difference Quotient

Formulas

Difference Quotient: (f(x+h) - f(x)) / h
Expansion of (x+h)^2 = x^2 + 2xh + h^2

Theorems

Difference Quotient Definition

Suitable Grade Level

Grade 10-12 (Calculus Preparation)