Understanding Quadratics
Grade 10 Academics
Standard Form
Standard Form is written as y = ax² + bx + c
Zeroes
To solve an equation given to us in standard form, one must put it in the quadratic equation which is: -b+-√b²-4(a)(c)
2(a)
This will allows us to find the x- intercepts in a standard form equation.
For instance we may come along the equation: y= 2x​​​²+6x+3
We would then need to plug it into
= -6+-√6²-4(2)(3)
2(2)
= -6+-√16
4
= -3-+4
4
x = 0.25 or -1.75
Axis of Symmetry
To find the AOS we would need to extract information from the standard form equation and put it into the equation: -b/2a
x= 2x​​​²+6x+3
x= -6/2(2)
x= -1.5
Optimal Value
Now we just have to sub in the x - intercept from the last step to get our optimal value.
y= 2(-1.5)​​​²+6(-1.5)+3
y= 4.5 -9 +3
y= -2.5
Vertex: (-1.5, -2.5)
Now we have completed how to find the vertex and x-intercepts when we encounter a standard form equation.
Completing the Square to Turn to Vertex Form
To change to vertex form we need a square.
y= x² +6x +7
we must devide b by two and then square it, add it into the equation just like I did:
y= (x² +6x + 9) -9 +7
y= (x+3)² -2
Now it is in vertex form
