Solve by Factoring
x^2=-5x
x=0,-5
3x^2=675
x=-15, 15
10x^2-x-4=0
x=-0.58, 0.68
5x^2-2x+5=0
-96; 0 real solutions
Some fireworks are fired into the air from the ground at an initial velocity of 80 feet per second.
Write an equation to represent this situation.
How high will the fireworks be after 1 second?
h=-16t^2+80t
64 feet
2x^2+8x-64=0
x=-8, 4
-7n^2=-182
n=-5.10, 5.10
2x^2+5x+7=7-3x
x=-4, 0
x^2+9=-6x
0; one solution
Some fireworks are fired into the air from the ground at an initial velocity of 80 feet per second.
Will the fireworks go above 75 feet?
1600; yes
x^3-5x^2-14x=0
x=-2, 0, 7
m^2+2=27
m=-5, 5
4x^2-4x+4=3
x=0.5
7x^2-2=4
168; two real solutions
Some fireworks are fired into the air from the ground at an initial velocity of 80 feet per second.
How long does it take the fireworks to reach the ground?
5 seconds
4x^2-9=0
x=-3/2, 3/2
(x+5)^2=10
x=-8.16, -1.84
3x^2-4x=8-4x
x=-1.63, 1.63
What part of the quadratic formula is the discriminant?
The number under the square root
b^2-4ac
A cannonball is shot upwards at a starting height of 4 feet with an initial velocity of 40 feet per second.
Write an equation to model this situation.
How high will the cannonball be after 1.25 seconds?
h=-16t^2+40t+4
29 feet
7x^2+2=15x
x=1/7, 2
-11(x+2)^2+704=0
x=-10, 6
16x^2-9x+4=9x^2-2
No real solution
What does the discriminant of a quadratic equation tell you about the equation?
How many solutions the quadratic equation will have (0, 1, or 2).
A cannonball is shot upwards at a starting height of 4 feet with an initial velocity of 40 feet per second.
Will the cannonball go over 30 feet?
-64; no.