Math Problem Statement

Find the coordinates of the vertex of the graph of the function y = -2x^2 - 4x + 4 and tell whether the vertex is a maximum or a minimum. Also, consider the quadratic function f(x) = x^2 + 3x - 10 and determine the vertex.

Solution

Let's go through the two questions in your image step by step.

Question 1:

The function given is y=2x24x+4y = -2x^2 - 4x + 4.

To find the vertex of a quadratic function y=ax2+bx+cy = ax^2 + bx + c, we use the vertex formula: x=b2ax = \frac{-b}{2a} For the given function:

  • a=2a = -2
  • b=4b = -4

Now, let's calculate xx: x=(4)2(2)=44=1x = \frac{-(-4)}{2(-2)} = \frac{4}{-4} = -1

Now that we have the xx-coordinate of the vertex, substitute x=1x = -1 back into the original equation to find the yy-coordinate: y=2(1)24(1)+4=2(1)+4+4=2+8=6y = -2(-1)^2 - 4(-1) + 4 = -2(1) + 4 + 4 = -2 + 8 = 6

Thus, the vertex is (1,6)(-1, 6).

Because the leading coefficient a=2a = -2 is negative, the parabola opens downwards, meaning the vertex is a maximum.

The correct answer is (1,6)(-1, 6); maximum.

Question 2:

The function given is f(x)=x2+3x10f(x) = x^2 + 3x - 10.

Again, we use the vertex formula: x=b2ax = \frac{-b}{2a} For this function:

  • a=1a = 1
  • b=3b = 3

Let's calculate xx: x=32(1)=32x = \frac{-3}{2(1)} = \frac{-3}{2}

Now substitute x=32x = -\frac{3}{2} back into the equation to find yy: f(32)=(32)2+3(32)10f\left(-\frac{3}{2}\right) = \left(-\frac{3}{2}\right)^2 + 3\left(-\frac{3}{2}\right) - 10

= \frac{9}{4} - \frac{18}{4} - \frac{40}{4} = \frac{9 - 18 - 40}{4} = \frac{-49}{4}$$ Thus, the vertex is $$\left( -\frac{3}{2}, -\frac{49}{4} \right)$$. --- Do you need more details on these solutions, or do you have any questions? Here are 5 related questions: 1. How do you derive the vertex formula for quadratic functions? 2. What is the significance of the sign of the leading coefficient in a quadratic function? 3. How do you complete the square to find the vertex of a quadratic function? 4. Can the vertex formula be used for non-standard quadratic functions (e.g., those with transformations)? 5. How does the vertex relate to the axis of symmetry in a quadratic function? **Tip:** Always check whether the parabola opens upwards or downwards based on the sign of the leading coefficient $$a$$, as this determines whether the vertex is a minimum or maximum point.

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Functions
Parabolas
Vertex of a Quadratic Function

Formulas

Vertex formula: x = -b/(2a)
Quadratic equation: y = ax^2 + bx + c

Theorems

Vertex formula theorem
Properties of parabolas

Suitable Grade Level

Grades 9-10