Math Problem Statement

Identify the vertex and the y-intercept then graph f(x) = -x^2 + 4x + 3.

Solution

The equation given in the image is f(x)=x2+4x+3f(x) = -x^2 + 4x + 3, which is a quadratic function. To identify the vertex and the y-intercept, let's break it down.

1. Finding the Vertex:

The equation is in standard form f(x)=ax2+bx+cf(x) = ax^2 + bx + c. For a quadratic function ax2+bx+cax^2 + bx + c, the vertex xx-coordinate is given by: x=b2ax = \frac{-b}{2a} In your equation, a=1a = -1, b=4b = 4, and c=3c = 3. So: x=42(1)=2x = \frac{-4}{2(-1)} = 2 Now, substitute x=2x = 2 back into the equation to find the yy-coordinate of the vertex: f(2)=(2)2+4(2)+3=4+8+3=7f(2) = -(2)^2 + 4(2) + 3 = -4 + 8 + 3 = 7 Thus, the vertex is (2,7)(2, 7).

2. Finding the Y-Intercept:

The y-intercept occurs when x=0x = 0. Substituting x=0x = 0 into the equation: f(0)=(0)2+4(0)+3=3f(0) = -(0)^2 + 4(0) + 3 = 3 Thus, the y-intercept is (0,3)(0, 3).

Summary:

  • Vertex: (2,7)(2, 7)
  • Y-Intercept: (0,3)(0, 3)

Would you like details on how to graph it, or do you have further questions?

Related Questions:

  1. How do you graph quadratic functions step by step?
  2. What is the importance of the axis of symmetry in a parabola?
  3. How do you calculate the roots of a quadratic equation using factoring or the quadratic formula?
  4. What is the significance of the sign of aa (whether the parabola opens upwards or downwards)?
  5. How does the vertex form of a quadratic function compare to the standard form?

Tip:

The vertex form of a quadratic function is useful for quickly identifying the vertex without needing calculations. You can rewrite the standard form to the vertex form by completing the square!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Quadratic Functions
Graphing
Vertex
Y-Intercept

Formulas

Vertex formula: x = -b / (2a)
Quadratic equation standard form: ax^2 + bx + c
Y-Intercept: f(0)

Theorems

Properties of Quadratic Functions

Suitable Grade Level

Grades 9-10