Given:
The vertex of a quadratic function is (4,-7).
To find:
The equation of the quadratic function.
Solution:
The vertex form of a quadratic function is:
...(i)
Where a is a constant and (h,k) is vertex.
The vertex is at point (4,-7).
Putting h=4 and k=-7 in (i), we get
The required equation of the quadratic function is where, a is a constant.
Putting a=1, we get
![[\because (a-b)^2=a^2-2ab+b^2]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%28a-b%29%5E2%3Da%5E2-2ab%2Bb%5E2%5D)
Therefore, the required quadratic function is .
A question such as this one is a little tricky since the people seated are not in a straight line.
For a circular table seating question, (n-1)! formula is used. Without restrictions 5! people can be seated.
You might be wondering why it is not 6!, this is because the first person will the the 6 person so you are accounting for the same person twice.
Hope I helped :)
<span>(2) y is the total cost, x is the number of months of service, $40 is the installation fee, and $90 is the service charge per month.</span>
y = 40 + 90x
y = total cost
x = number of months of service
40 = one time installation fee
90 = monthly service charge.
Let us assume that the number of months of service is 10 months. then, the total cost would be:
y = 40 + 90(10)
y = 40 + 900
y = 940
