- Vertex/General Form: y = a(x - h)^2 + k, with (h,k) as the vertex
- (x + y)^2 = x^2 + 2xy + y^2
- Standard Form: y = ax^2 + bx + c
So before I put the equation into standard form, I'm first going to be putting it into vertex form. Since the vertex appears to be (-1,7), plug that into the vertex form formula:
Next, we need to solve for a. Looking at this graph, another point that is in this line is the y-intercept (0,5). Plug (0,5) into the x and y placeholders and solve for a as such:
Now we know that <u>our vertex form equation is y = -2(x + 1)^2 + 7.</u>
However, we need to convert this into standard form still, and we can do it as such:
Firstly, solve the exponent: 
Next, foil -2(x^2+2x+1): 
Next, combine like terms and <u>your final answer will be: 
</u>
E because its not on there
Answer: The graph has the answer
Answer:
Take x = 10.2 in. or x = 10 in.
Step-by-step explanation:
Given :
Length = (2x+3) in.
Breadth = x in.
Also, the Area of Rectangle = 240 sq in.
We know that,
Area of Rectangle = length x breadth
240 = (2x+3) x
2x² + 3x = 240
2x² + 3x - 240 = 0
Solving 2x²+3x-240 = 0 by the Quadratic Formula .
According to the Quadratic Formula, x , the solution for Ax2+Bx+C = 0 , where A, B and C are numbers, often called coefficients, is given by :
- B ± √ B²-4AC
x = ————————
2A
In our case, A = 2
B = 3
C = -240
Accordingly, B² - 4AC = 9 - (-1920) = 1929
Applying the quadratic formula :
-3 ± √ 1929
x = ——————
4
√ 1929 , rounded to 4 decimal digits, is 43.9204
So now we are looking at:
x = ( -3 ± 43.920 ) / 4
Two real solutions:
x =(-3+√1929)/4=10.230 ≈ 10
or
x =(-3-√1929)/4=-11.730
We'll take x = +ve value for calculation of length and breadth.
Therefore,
Length = [2(10.2) + 3 ]
L = 23.4 in.
Breadth = 10.2 in.
OR
Length = [2(10) + 3]
L = 23 in.
Breadth = 10 in.
the first one y= 4x (8 - x)
