Math Problem Statement

give me answer

If f(x) = x^2 - 3x + 7, then show that (f(x+h) - f(x))/h = 2x - 3 + h.

Solution

The problem asks to show that:

f(x+h)f(x)h=2x3+h\frac{f(x+h) - f(x)}{h} = 2x - 3 + h

where the function f(x)=x23x+7f(x) = x^2 - 3x + 7.

Step-by-Step Solution:

  1. Start by calculating f(x+h)f(x+h): f(x+h)=(x+h)23(x+h)+7f(x+h) = (x+h)^2 - 3(x+h) + 7 Expanding this expression: f(x+h)=x2+2xh+h23x3h+7f(x+h) = x^2 + 2xh + h^2 - 3x - 3h + 7

  2. Now calculate f(x+h)f(x)f(x+h) - f(x): Using f(x)=x23x+7f(x) = x^2 - 3x + 7, we subtract: f(x+h)f(x)=(x2+2xh+h23x3h+7)(x23x+7)f(x+h) - f(x) = \left( x^2 + 2xh + h^2 - 3x - 3h + 7 \right) - \left( x^2 - 3x + 7 \right) Simplifying this: f(x+h)f(x)=2xh+h23hf(x+h) - f(x) = 2xh + h^2 - 3h

  3. Divide by hh: f(x+h)f(x)h=2xh+h23hh\frac{f(x+h) - f(x)}{h} = \frac{2xh + h^2 - 3h}{h} Simplify each term: f(x+h)f(x)h=2x+h3\frac{f(x+h) - f(x)}{h} = 2x + h - 3

  4. Conclusion: f(x+h)f(x)h=2x3+h\frac{f(x+h) - f(x)}{h} = 2x - 3 + h This confirms the given statement.

Let me know if you need further explanation or details!


Here are 5 related questions to deepen understanding:

  1. What is the significance of finding f(x+h)f(x)h\frac{f(x+h) - f(x)}{h} in calculus?
  2. How does this relate to the concept of the derivative?
  3. What is the derivative of the given function f(x)=x23x+7f(x) = x^2 - 3x + 7?
  4. What happens as h0h \to 0 in this expression?
  5. How would you approach the problem if f(x)f(x) were a different type of function, like a cubic function?

Tip: The expression f(x+h)f(x)h\frac{f(x+h) - f(x)}{h} is known as the difference quotient, which leads to the derivative of a function as h0h \to 0.

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Math Problem Analysis

Mathematical Concepts

Algebra
Functions
Difference Quotient
Calculus

Formulas

f(x) = x^2 - 3x + 7
Difference quotient: (f(x+h) - f(x))/h

Theorems

Difference Quotient
Basic Function Derivatives

Suitable Grade Level

Grades 10-12