Do the ratios 4 5 and 13 15 form a proportion?
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Answer:
Step-by-step explanation:
The quadratic equation in its standard form is:
Now, we are given 5 points of the parabola (if you graph a quadratic equation you will have a parabola), however we only need to choose three points to find the coeficients ,
and
in the quadratic equation.
So, let's choose the first three points:
(-1,14):
(1)
(0,7):
(2)
(1,4):
(3)
Substituting (2) in (1) and (3):
(4)
(5)
At this point we have a system with two equations.
Adding (4) to (5):
(6)
Isolating :
(7)
Substituitng (7) in (3):
(8)
Isolating :
(9)
Now we have the three coeficients and we can write the quadratic equation: