What is the general formula to find the vertex of a quadratic function written in standard form (ax2 + bx + c)?
ax^2 + bx + c (1)
In this form, the x coordinate of the vertex is given by
- b / [ 2* a ]
To find the y coordinate, sub this result back into (1)
Examlple
2x^2 + 8x + `10 ...... a = 2 b = 8
x coordinate of the vertex = -8/ [2 * 2 ] = -8 / [ 2 * 2 ] = -8 / 4 = -2
y coordinate of the vertex = 2 (-2)^2 + 8(-2) + 10 = 2