Math Problem Statement

Consider the parabola given by the equation: f(x) = 2x^2 - 10x - 14. Find the following: A) The vertex, B) The vertical intercept, C) The coordinates of the two x-intercepts.

Solution

Let's solve the quadratic function f(x)=2x210x14f(x) = 2x^2 - 10x - 14 by finding the required points step by step:

A) Finding the Vertex:

The vertex of a parabola given by f(x)=ax2+bx+cf(x) = ax^2 + bx + c is found using the formula: xvertex=b2ax_{\text{vertex}} = -\frac{b}{2a} For f(x)=2x210x14f(x) = 2x^2 - 10x - 14, we have:

  • a=2a = 2
  • b=10b = -10

Using the vertex formula: xvertex=102(2)=104=2.5x_{\text{vertex}} = -\frac{-10}{2(2)} = \frac{10}{4} = 2.5

To find the yy-coordinate of the vertex, plug x=2.5x = 2.5 back into the equation: f(2.5)=2(2.5)210(2.5)14=2(6.25)2514=12.52514=26.5f(2.5) = 2(2.5)^2 - 10(2.5) - 14 = 2(6.25) - 25 - 14 = 12.5 - 25 - 14 = -26.5

Thus, the vertex is (2.5,26.5)(2.5, -26.5).

B) Vertical Intercept (y-intercept):

The vertical intercept is the point where x=0x = 0. Substituting x=0x = 0 into the equation: f(0)=2(0)210(0)14=14f(0) = 2(0)^2 - 10(0) - 14 = -14 Thus, the vertical intercept is (0,14)(0, -14).

C) Finding the x-intercepts:

To find the x-intercepts, solve f(x)=0f(x) = 0: 2x210x14=02x^2 - 10x - 14 = 0 We can use the quadratic formula: x=b±b24ac2ax = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} For a=2a = 2, b=10b = -10, and c=14c = -14: x=(10)±(10)24(2)(14)2(2)=10±100+1124=10±2124x = \frac{-(-10) \pm \sqrt{(-10)^2 - 4(2)(-14)}}{2(2)} = \frac{10 \pm \sqrt{100 + 112}}{4} = \frac{10 \pm \sqrt{212}}{4} 21214.56\sqrt{212} \approx 14.56 Thus, the x-intercepts are: x=10+14.564=24.564=6.14x = \frac{10 + 14.56}{4} = \frac{24.56}{4} = 6.14 x=1014.564=4.564=1.14x = \frac{10 - 14.56}{4} = \frac{-4.56}{4} = -1.14

So, the x-intercepts are approximately (6.14,0)(6.14, 0) and (1.14,0)(-1.14, 0).

Summary:

  • A) Vertex: (2.5,26.5)(2.5, -26.5)
  • B) Vertical intercept: (0,14)(0, -14)
  • C) x-intercepts: (6.14,0),(1.14,0)(6.14, 0), (-1.14, 0)

Would you like more details or have any questions?

Here are 5 related questions:

  1. How do you derive the quadratic formula?
  2. What is the significance of the vertex in a quadratic function?
  3. Can a parabola have more than two x-intercepts?
  4. How does the value of 'a' affect the shape of the parabola?
  5. What is the axis of symmetry for this quadratic function?

Tip: The discriminant b24acb^2 - 4ac in the quadratic formula tells you the nature of the roots: if positive, there are two real roots; if zero, one real root; if negative, no real roots.

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Math Problem Analysis

Mathematical Concepts

Quadratic Functions
Vertex
Intercepts

Formulas

Vertex formula: x = -b / 2a
Quadratic formula: x = (-b ± √(b² - 4ac)) / 2a

Theorems

Quadratic formula
Symmetry of parabolas

Suitable Grade Level

Grades 9-11