Math Problem Statement

Evaluate each of the following expressions, where h is a variable. Let f(x) = 4 - x^2.

Solution

Let's analyze the problem from the image.

The function is given as:

f(x)=4x2f(x) = 4 - x^2

Part (A):

You are asked to evaluate:

f(9)f(5)95\frac{f(9) - f(5)}{9 - 5}

First, compute f(9)f(9) and f(5)f(5).

f(9)=492=481=77f(9) = 4 - 9^2 = 4 - 81 = -77 f(5)=452=425=21f(5) = 4 - 5^2 = 4 - 25 = -21

Now, substitute these values into the expression:

f(9)f(5)95=77(21)4=77+214=564=14\frac{f(9) - f(5)}{9 - 5} = \frac{-77 - (-21)}{4} = \frac{-77 + 21}{4} = \frac{-56}{4} = -14

So, the answer to Part (A) is:

14\boxed{-14}

Part (B):

You are asked to evaluate the following limit-like expression:

f(5+h)f(5)h\frac{f(5 + h) - f(5)}{h}

We already know that f(5)=21f(5) = -21. Now, let's compute f(5+h)f(5 + h):

f(5+h)=4(5+h)2=4(25+10h+h2)=42510hh2=2110hh2f(5 + h) = 4 - (5 + h)^2 = 4 - (25 + 10h + h^2) = 4 - 25 - 10h - h^2 = -21 - 10h - h^2

Now, substitute this into the expression:

f(5+h)f(5)h=2110hh2(21)h=10hh2h=10h\frac{f(5 + h) - f(5)}{h} = \frac{-21 - 10h - h^2 - (-21)}{h} = \frac{-10h - h^2}{h} = -10 - h

So, the answer to Part (B) is:

10h\boxed{-10 - h}

Would you like further clarifications or details?

Here are 5 related questions you can explore:

  1. What is the derivative of the function f(x)=4x2f(x) = 4 - x^2?
  2. How do you interpret the result of Part (B) in terms of calculus (hint: it's a difference quotient)?
  3. What happens to the expression in Part (B) as h0h \to 0?
  4. Can you generalize the difference quotient for f(x)f(x) at any point aa instead of just 5?
  5. What is the significance of negative values in the function f(x)=4x2f(x) = 4 - x^2?

Tip: The expression in Part (B) is closely related to the concept of the derivative in calculus. Understanding how these difference quotients behave as h0h \to 0 is key to grasping differentiation.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Quadratic Functions
Difference Quotient
Algebra

Formulas

f(x) = 4 - x^2
Difference Quotient: (f(9) - f(5)) / (9 - 5)
General Difference Quotient: (f(5 + h) - f(5)) / h

Theorems

Difference Quotient Theorem
Derivative Concept

Suitable Grade Level

Grade 11-12 (Precalculus/Calculus)