find the vertex of y= x2 +5x +4

Question

find the vertex of y =x2 +5x +4

 

Answer 1

Y=AX^2+Bx+C is the general form of a quadratic equation

to find the vertex use:-B/(2A) for the x coordinate.    -5/(2*1)=-2.5= x

then plug x value into equation to get y coordinate:  

y= (-2.5)^2+5(-2.5)+4=6.25+-12.5+4=-2.25=y

vertex is (x,y)

so vertex is (-2.5,-2.25)

Answer 2

Standard (general) form of quadratic function:
y = ax² + bx + c (all letters are in low case!)
(Standard (general) form of quadratic equation: ax² + bx + c = 0)
Formula to find the x-coordinate of vertex is
x = - b / (2a)

y = x² + 5x + 4 
a = 1, b = 5, c = 4
x = -5/2 = - 2.5
y = (-2.5)² + 5(-2.5) + 4 = 6.25 - 12.5 + 4 = - 2.25
Coordinates of vertex are (- 2.5, - 2.25)