When the equation of the parabola is in this form:
y = ax2 + bx + c
The x-coordinate of the turning point = - b2a
----------
For example, if the equation of the parabola is
y = 3x2 + 4x + 1
The x-coordinate of the turning point = - 42(3) = - 23
Plug this in for x to find the value of the y-coordinate.
y = 3( - 23 )2 + 4( - 23 ) + 1 = - 13
So the turning point is ( - 23, - 13 )
When the equation of the parabola is in this form:
y = ax2 + bx + c
The x-coordinate of the turning point = - b2a
----------
For example, if the equation of the parabola is
y = 3x2 + 4x + 1
The x-coordinate of the turning point = - 42(3) = - 23
Plug this in for x to find the value of the y-coordinate.
y = 3( - 23 )2 + 4( - 23 ) + 1 = - 13
So the turning point is ( - 23, - 13 )