Math Problem Statement

Consider the function f(x) = x^2 + 2x + 1 and evaluate the specified values: a. f(a), b. f(a+h), and c. (f(a+h)-f(a))/h.

Solution

Let's solve the questions based on the function provided:

The function is:

f(x)=x2+2x+1f(x) = x^2 + 2x + 1

a. f(a)f(a)

To find f(a)f(a), substitute aa for xx in the function f(x)f(x):

f(a)=a2+2a+1f(a) = a^2 + 2a + 1

b. f(a+h)f(a+h)

To find f(a+h)f(a+h), substitute a+ha + h for xx in the function:

f(a+h)=(a+h)2+2(a+h)+1f(a+h) = (a+h)^2 + 2(a+h) + 1

Now expand this expression:

(a+h)2=a2+2ah+h2(a+h)^2 = a^2 + 2ah + h^2 2(a+h)=2a+2h2(a+h) = 2a + 2h

Thus:

f(a+h)=a2+2ah+h2+2a+2h+1f(a+h) = a^2 + 2ah + h^2 + 2a + 2h + 1

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

Now, calculate the difference quotient:

f(a+h)f(a)h=(a2+2ah+h2+2a+2h+1)(a2+2a+1)h\frac{f(a+h) - f(a)}{h} = \frac{(a^2 + 2ah + h^2 + 2a + 2h + 1) - (a^2 + 2a + 1)}{h}

Simplify the expression in the numerator:

=a2+2ah+h2+2a+2h+1a22a1= a^2 + 2ah + h^2 + 2a + 2h + 1 - a^2 - 2a - 1

After cancellation, we are left with:

=2ah+h2+2h= 2ah + h^2 + 2h

Thus, the expression becomes:

2ah+h2+2hh\frac{2ah + h^2 + 2h}{h}

Now, factor out hh from the numerator:

=h(2a+h+2)h= \frac{h(2a + h + 2)}{h}

Cancel the hh:

=2a+h+2= 2a + h + 2

So:

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


Would you like more details or have any questions about this solution?

Here are 5 related questions to explore:

  1. What is the meaning of the difference quotient in calculus?
  2. How would you find the derivative of f(x)=x2+2x+1f(x) = x^2 + 2x + 1 using limits?
  3. How does the expression f(a+h)f(a)h\frac{f(a+h) - f(a)}{h} lead to the derivative when h0h \to 0?
  4. Can you apply the same method to find the difference quotient for a cubic function?
  5. How does the difference quotient represent the slope of the tangent line at a point?

Tip: The difference quotient is an important step toward understanding the derivative of a function, which gives the rate of change at any point.

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Math Problem Analysis

Mathematical Concepts

Algebra
Functions
Difference Quotient
Quadratic Functions

Formulas

f(x) = x^2 + 2x + 1
f(a) = a^2 + 2a + 1
f(a+h) = (a+h)^2 + 2(a+h) + 1
(f(a+h) - f(a)) / h = (2ah + h^2 + 2h) / h = 2a + h + 2

Theorems

Difference Quotient Formula

Suitable Grade Level

Grades 10-12