To Find :
The equation of the quadratic whose Vertex is at ( −4,−5) and passes through the point (−3, −7).
Solution :
A quadratic equation in vertex form is given by :
( Here, h, k is the vertex )
y = a(x-(-4))² + (-5)
y = a(x+4)² - 5
Now, putting (-3,-7) in above equation:
-7 = a( -3 + 4 )² - 5
a(1)² = -2
a = -2
Therefore, the equation of the quadratic is y = -2(x+4)² - 5 .
Answer:
The time it took until 2 inches of rain fell is 8 hours
Step-by-step explanation:
You know that the proportional relationship between the amount of time (in hours) it had been raining, x, and the amount of rain (in inches) it had fallen, y, is y = 0.25*x
To find the time that passed until 2 inches of rain fell, you must replace the amount of rain (in inches) that had fallen "and" by that value. In this way the following expression is obtained:
2= 0.25*x
Solving:
8 = x
So, remembering that the amount of time it had been raining, x, is expressed in hours, <u><em>the time it took until 2 inches of rain fell is 8 hours</em></u>.