Math Problem Statement

Given f(x) = 2x² + 5x-3, find f(x²-3)

Solution

To find f(x23)f(x^2 - 3), we need to substitute x23x^2 - 3 into the function f(x)=2x2+5x3f(x) = 2x^2 + 5x - 3 wherever there is an xx.

  1. Start with the original function:
    f(x)=2x2+5x3f(x) = 2x^2 + 5x - 3

  2. Substitute x23x^2 - 3 for xx in the function: f(x23)=2(x23)2+5(x23)3f(x^2 - 3) = 2(x^2 - 3)^2 + 5(x^2 - 3) - 3

  3. Now, expand and simplify each term:

    • First, expand (x23)2(x^2 - 3)^2: (x23)2=x46x2+9(x^2 - 3)^2 = x^4 - 6x^2 + 9
    • Now, multiply by 2: 2(x23)2=2(x46x2+9)=2x412x2+182(x^2 - 3)^2 = 2(x^4 - 6x^2 + 9) = 2x^4 - 12x^2 + 18
    • Next, expand 5(x23)5(x^2 - 3): 5(x23)=5x2155(x^2 - 3) = 5x^2 - 15
    • Finally, combine all terms: f(x23)=2x412x2+18+5x2153f(x^2 - 3) = 2x^4 - 12x^2 + 18 + 5x^2 - 15 - 3
  4. Simplify: f(x23)=2x4+(12x2+5x2)+(18153)f(x^2 - 3) = 2x^4 + (-12x^2 + 5x^2) + (18 - 15 - 3) f(x23)=2x47x2+0f(x^2 - 3) = 2x^4 - 7x^2 + 0

Thus, the simplified expression is: f(x23)=2x47x2f(x^2 - 3) = 2x^4 - 7x^2

Would you like more details or have any questions?

Here are five related questions to expand your understanding:

  1. What is the derivative of f(x23)f(x^2 - 3)?
  2. How would you solve f(x23)=0f(x^2 - 3) = 0?
  3. What happens to f(x23)f(x^2 - 3) as xx \to \infty?
  4. How do the roots of f(x23)=0f(x^2 - 3) = 0 compare to the roots of f(x)=0f(x) = 0?
  5. How would you graph f(x23)f(x^2 - 3)?

Tip: Always simplify step by step when performing substitutions, especially when dealing with polynomial expressions.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Algebra
Function Substitution
Polynomial Expansion

Formulas

f(x) = 2x² + 5x - 3
Substitution: f(g(x))
Polynomial Expansion Formula: (a + b)² = a² + 2ab + b²

Theorems

-

Suitable Grade Level

Grades 9-11