Math Problem Statement

Evaluate the limit: lim_{h \to 0} \frac{(4 + h)^2 - 16}{h}

Solution

Let's go through the steps shown in the image to evaluate the limit:

We are asked to evaluate the limit:

limh0(4+h)216h\lim_{h \to 0} \frac{(4 + h)^2 - 16}{h}

Step 1: Define F(h)F(h)

Define F(h)F(h) as the expression inside the limit:

F(h)=(4+h)216hF(h) = \frac{(4 + h)^2 - 16}{h}

Step 2: Expand (4+h)2(4 + h)^2

Next, expand (4+h)2(4 + h)^2:

(4+h)2=16+8h+h2(4 + h)^2 = 16 + 8h + h^2

Now substitute this into F(h)F(h):

F(h)=16+8h+h216hF(h) = \frac{16 + 8h + h^2 - 16}{h}

Simplify the numerator:

F(h)=8h+h2hF(h) = \frac{8h + h^2}{h}

Step 3: Simplify the Expression

Factor the numerator:

F(h)=h(8+h)hF(h) = \frac{h(8 + h)}{h}

For h0h \neq 0, we can cancel hh from the numerator and denominator:

F(h)=8+hF(h) = 8 + h

Step 4: Take the Limit as h0h \to 0

Now, take the limit of F(h)F(h) as h0h \to 0:

limh0(8+h)=8\lim_{h \to 0} (8 + h) = 8

Final Answer:

The limit is:

limh0(4+h)216h=8\lim_{h \to 0} \frac{(4 + h)^2 - 16}{h} = 8


Would you like more details about any step or have further questions?

Here are 5 related questions for deeper understanding:

  1. How would you approach this problem using L'Hôpital's Rule?
  2. Why can't we directly substitute h=0h = 0 at the start?
  3. What does the cancellation of hh in the numerator and denominator represent geometrically?
  4. How does this limit relate to the concept of derivatives?
  5. How can we apply similar techniques to evaluate the limit of a different quadratic expression?

Tip: When simplifying limits involving a difference of squares, expanding the binomial and factoring terms is often key to canceling problematic terms.

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Math Problem Analysis

Mathematical Concepts

Limits
Algebra
Quadratic Expansion

Formulas

(a + b)^2 = a^2 + 2ab + b^2
Limit as h approaches 0

Theorems

Limit Laws
Factorization

Suitable Grade Level

Grades 11-12 or Early College