NEW
Font size
WorksheetsFINDING QUADRATIC FUNCTION/EQUATION
Total questions: 15
Worksheet time: 22mins
Write the equation of the quadratic
whose roots are -4, -2.
x2-6x+8
x2+6x+8
x2-4x-2
x2-2x-4
Write the quadratic equation given the zeros(roots) are -4 and 5 and a = 1.
(x + 4) (x - 5) = 0
(x - 4) (x + 5)=0
(x + 4) ( x + 5)=0
(x - 4) (x - 5)=0
Write the equation of the quadratic function that has a x-intercepts at (2, 0) and (4, 0) and passes through the point (3, 4).
y = -4(x - 2)(x - 4)
y = -4(x + 2)(x + 4)
y = 4(x - 2)(x - 4)
y = -0.25(x - 2)(x - 4)
Identify the y-intercept
(0, -3)
(0, 1)
(0, 3)
(2, 1)
A
B
C
D
Write a quadratic equation given the x intercepts and one other point.
Step 1: Write the factors.
The intercepts of this function are (6, 0) and (8, 0). Write the factors.
(x-6) and (x-8)
(x+6) and (x+8)
(x-6) and (x+8)
(x+6) and (x-8)
Write a quadratic equation given the x intercepts and one other point.
Step 2: Find a.
Now that you know that the factors are (x-6) and (x-8), you must find a. Plug the coordinates of the vertex (7, 1) in for x and y and solve for a.
y = a(x-6)(x-8)
What is the value of a?
a = 1
a = -1
a = 7
a = -7
Write a quadratic equation given the x intercepts and one other point.
Step 3: Write the equation in factored form.
Now, you know that the factors are (x-6) and (x-8) and a = -1. Write the equation of the graph in factored form.
-(x-6)(x-8)
-(x+6)(x+8)
(x-6)(x+8)
(x+6)(x-8)
Now, take the factored form and write it in Standard Form (ax2+bx+c=0) by double distributing (or FOIL).
-(x-6)(x-8)=0
x2+2x-15=0
-x2+14x -48=0
- x2+8x-15=0
x2 + 5x -16=0
Write a quadratic equation given the x intercepts and one other point.
Put the steps together.
Find the factors. Solve for a by substituting in the extra point. Write the equation in factored form.
The roots of the function are (-3, 0) and (5, 0).
The point (4, -3) is also on the graph.
y=4(x+3)(x-5)
y=3/7(x-3)(x+5)
y=-3(x-3)(x+5)
y=3/7(x+3)(x-5)
Write a quadratic equation in vertex form given the vertex and another point.
- Substitute the coordinates of the vertex (1, -4) in for h and k.
Vertex form: y=a(x-h)2+k
(x+1)2-4=y
(x-1)2-4=y
(x + 1)(x - 3)=y
x2 +2x - 3=y
