State whether the parabola opens up or down and find the y-intercept:
y=x2+3x+9
Open up, (0,9)
How many x-Intercepts does the following function have?
y=-2x2+4x+1
Two X-Intercepts
What does the graph of an axis of symmetry, for example the line x=3, look like?
Straight Vertical Line
Write the quadratic equation of the graph given below in vertex form.
y = 2/3 (x - 3)2 + 1
Solve for x by taking square roots:
2(x-1)2-7=3
x=1+/- squareroot(5)
State whether the parabola opens up or down and find the y-intercept:
y=-3x2+7x-5
Open Down, (0,-5)
Find the x-intercepts of the function:
y=2x2-2x-5
(1+sqaureroot(11)/2,0) and (1-sqaureroot(11)/2,0)
What is important about the axis of symmetry?
It is the line across which the parabola is symmetrical, or a mirror image of itself.
Find the y-int., the AOS, the vertex and the approximate roots of this function:
(0, -2)
x = 0
Vertex: (0, -2)
Roots={-1.5, 1.5}
Solve by completing the square:
3x2 + 18x - 63 = 0
x= -3 + sqroot of 30 and
x= -3 - sqroot of 30
State whether the parabola opens up or down and find the y-intercept:
y=-x2+4
Open Down, (0,4)
Find the X-Intercepts of the function:
y=4x2-5x-6
(-3/4,0) and (2,0)
Find the axis of symmetry for the following function:
y=x2-3x+4
x=3/2
Graph the following function:
y=x2 - 2x - 8
,7/2)
Solve by completing the square:
x2+6x-3=0
x=-3+/- 2squareroot(3)
State whether the parabola opens up or down and find the y-intercept:
y=2x2
Open Up, (0,0)
Find the x-intercept(s) of the function:
y=4x2-12x+9
(3/2,0)
Find the axis of symmetry and the vertex of the following function:
y=-4x2+8x-9
Axis of Symmetry: x=1
Vertex: (1, -5)
Write the equation of the parabola given below in vertex form.
y= -1/3(x - 1.5)2 + 3
A factory produces shoes. They want to determine the number of pair of shoes that will maximize their revenues and they have asked you to do it for them. The factory uses the model
r(s) = -18x2 + 117000x - 2865500.
a) Determine the number of pairs of shoes they need to produce.
b) Determine the maximum revenue they will receive.
a) 3250 pairs of shoes
b) They will receive $282,322,000
State whether the parabola opens up or down and find the y-intercept:
y=-3x2+2x
Open Down, (0,0)
Give an example of a quadratic function that has no x-intercepts.
-
Find the vertex of the function:
y=2x2-2x+4
(1/2,7/2)
Graph the equation y = -x2 + 4x - 3
An object is thrown from a cliff that is 3250 feet high. Its fall follows the model
y=-16t2 - 192t + 3250 .
a) How many feet will it fall between 3 and 4 seconds?
b) After how many seconds does it hit the ground?
Figure it out!!