Finding the Vertex of a Parabola
The vertex of a parabola described by the quadratic equation in the form of y = ax² + bx + c can be found using the vertex formula:
x-coordinate of vertex = -b / (2a)
Step-by-Step Calculation
Given the equation:
y = 2x² + 8x + 5
Here, we identify:
- a = 2
- b = 8
- c = 5
Calculate the x-coordinate:
Using the formula:
x = -b / (2a)
Plugging in the values:
x = -8 / (2 * 2) = -8 / 4 = -2
Calculate the y-coordinate:
Now that we have the x-coordinate of the vertex, we can find the y-coordinate by substituting x back into the original equation:
y = 2(-2)² + 8(-2) + 5
Calculating this:
- 2 * 4 = 8
- 8 * -2 = -16
Therefore:
y = 8 – 16 + 5 = -3
Conclusion
The coordinates of the vertex are:
(-2, -3)
This means that the vertex of the parabola given by the equation y = 2x² + 8x + 5 is at the point (-2, -3).