6)
A quadratic function has the form
y = ax^2 + bx + c
Use point (3, 5) in the equation above:
5 = a(3^2) + 3b + c
5 = 9a + 3b + c
9a + 3b + c = 5 Equation 1
Use point (4, 3) in the equation above:
3 = a(4^2) + 4b + c
16a + 4b + c = 3 Equation 2
Use point (5, 3) in the equation above.
5 = a(5^2) + 5b + c
25a + 5b + c = 5 Equation 3.
Now solve the system of equations of equations 1, 2, and 3 to find the coefficients, a, b, and c.
9a + 3b + c = 5
16a + 4b + c = 3
25a + 5b + c = 5
Subtract the first equation from the second equation.
Subtract the second equation from the third equation.
You get
7a + b = -2
9a + b = 2
Subtract the first equation above from the second equation to get.
2a = 4
a = 2
Substitute:
7a + b = -2
7(2) + b = -2
b = -16
9a + 3b + c = 5
9(2) + 3(-16) + c = 5
18 - 48 + c = 5
c - 30 = 5
c = 35
The equation in standard form is
y = 2x^2 - 16x + 35
We can find it in vertex form:
y = 2(x^2 - 8x) + 35
y = 2(x^2 - 8x + 16) + 35 - 32
y = 2(x - 4)^2 + 3
<span> (y2-y1) that's the formula </span>
Answer:
I don't really know the answer because I don't
Step-by-step explanation:
I think 24 might be the answer if not its 15
Answer:
b = 3 and a = -1
Step-by-step explanation:
You have your given equation:
2a - 3b = -11
a + 3b = 8
You need to find what a and b is.
To find b:
2a - 3b = -11
-2a - 6b = -16
I multiplied a + 3b = 8 by -2. When you multiply a number you have to multiply all of them. You have to choose a number that would cancel out all of a.
So now your equation would look like this when you solve for b:
2a - 3b = -11
-2a - 6b = -16
-------------------
a - 9 = -27 then you divide -9 to -27 which is 3 so b = 3.
To find a:
2a - 3b = -11
a + 3b = 8
I multiplied a + 3b = 8 by -1 and 2a - 3b = -11 by -1 as well.
Your equation will look like this when you solve for a:
-2a + 3b = 11
-1a - 3b = -8
------------------
-3a = 3 then divide -3 to 3 which is -1 so a = -1.
Check to see if you have the correct answer by plugging in the number you got for a and b into the equation and solve.
1. 2(-1) -3(3) = -11
-2 - 9 = -11
2. -1 + 3(3) = 8
-1 + 9 = 8
