Math Problem Statement

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

Solution

Let's break down and solve the problem step by step, based on the image:

Given: f(x)=5x2+3f(x) = 5x^2 + 3

1. Finding f(a)f(a):

To find f(a)f(a), substitute x=ax = a into the function: f(a)=5a2+3f(a) = 5a^2 + 3

2. Finding f(a+h)f(a + h):

Next, substitute x=a+hx = a + h into the function: f(a+h)=5(a+h)2+3f(a + h) = 5(a + h)^2 + 3 Expand the square: f(a+h)=5(a2+2ah+h2)+3=5a2+10ah+5h2+3f(a + h) = 5(a^2 + 2ah + h^2) + 3 = 5a^2 + 10ah + 5h^2 + 3

3. Finding the difference quotient:

The difference quotient is given by: f(a+h)f(a)h\frac{f(a + h) - f(a)}{h} Substitute the expressions for f(a+h)f(a + h) and f(a)f(a): (5a2+10ah+5h2+3)(5a2+3)h\frac{(5a^2 + 10ah + 5h^2 + 3) - (5a^2 + 3)}{h} Simplify the numerator: 5a2+10ah+5h2+35a23h=10ah+5h2h\frac{5a^2 + 10ah + 5h^2 + 3 - 5a^2 - 3}{h} = \frac{10ah + 5h^2}{h} Factor out hh from the numerator: =h(10a+5h)h=10a+5h= \frac{h(10a + 5h)}{h} = 10a + 5h

Final answers:

  • f(a)=5a2+3f(a) = 5a^2 + 3
  • f(a+h)=5a2+10ah+5h2+3f(a + h) = 5a^2 + 10ah + 5h^2 + 3
  • f(a+h)f(a)h=10a+5h\frac{f(a + h) - f(a)}{h} = 10a + 5h

Would you like further details on any part of this process?

Here are five related questions you can explore:

  1. What is the significance of the difference quotient in calculus?
  2. How do we use the difference quotient to find the derivative of a function?
  3. How does expanding binomials relate to solving this problem?
  4. What happens if we let h0h \to 0 in the difference quotient?
  5. How would this problem change if the function were f(x)=x3+2f(x) = x^3 + 2?

Tip: The difference quotient is the foundation for understanding derivatives, which measure the rate of change of a function.

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Math Problem Analysis

Mathematical Concepts

Quadratic Functions
Difference Quotient
Algebra

Formulas

f(a) = 5a^2 + 3
f(a + h) = 5(a + h)^2 + 3
(f(a + h) - f(a)) / h = 10a + 5h

Theorems

Difference Quotient Theorem
Binomial Expansion

Suitable Grade Level

Grades 10-12