y = 2x2 − 4x − 2
x2 +10x + 7
y = x2 − 12x + 46
(6,10)
2x2 + 3x − 20 = 0
x= 5/2 x= -4
when do we use the AC method?
When the A is greater than 1
y = −3x 2 + 12x − 10
x = 2
Solve by completing the square!
x2 – 8x + 5 = 0
(x-4)2 -11
y = −x2 − 14x − 59
(-7,-11)
2m2 + 2m − 12 = 0
m=2 m= -3
When do we use the quadratic formula?
f (x) = −x 2 − 10x − 30
x = -5
Complete the square!
x2 + 12x + 4 = 0
(x+6) 2 -32
f (x) = 14 (x + 4)2 + 3
(-4,3)
m2 − 5m − 14 = 0
m= 7 m = -2
What happens if the value of B is a negative in the quadratic formula?
The first number becomes a positive but it DOES NOT effect the b2 term
f (x) = 3x 2 − 54x + 241
x=9
5x2 +20x +32 = 0
5(x+2)2 +12
f (x) = −2(x + 5)2 − 3
(-5,-3)
What is the quadratic formula and why do you use the quadratic formula?
-b +- the square root of b^2 -4ac divided by 2a to find the x-intercepts or roots of an equation
Johnny went to the store and bought 4 sodas and 6 hot dogs for $22. Jeremy went to the same store and bought 2 sodas and 4 hot dogs for $13.50. What is the cost of each hot dog and soda?
hot dogs $2.50 soda $1.75
f (x) = 1/4x2 − x + 9 .
x=8
Complete the square
4x2 +8x - 9
4(x+1)2 -13
y = 2x2 + 36x + 170
(-9,8)
2m2 − 7m − 13 = −10
7 Plus & Minus the square root of 73 divided by 4
Which equation has a greater correlation coefficient?
Is it R= .934 or R=-.945
R= -.945