Question

Can someone help me solve this and explain it?

Answer 1

a. -0.004
b. -sqrt(20)/70

Explanation:

a.

We are given that y = a(x - 70)^2 + 20

And we know that x=0 and y=0

We can substitute these values into the equation:

0 = a(-70)^2 + 20

Simplifying we get:

0 = a(4900) + 20

Subtracting 20 from both sides we get:

-20 = a(4900)

Dividing both sides by 4900 we get:

a = -20/4900

a = -20/4900 = -0.004

So the value of a is -0.004

b.
We are given that y = a(x - 70)^2 + 20

And we know that x=140 and y=0

We can substitute these values into the equation:

0 = a(140-70)^2 + 20

Simplifying we get:

0 = a(70)^2 + 20

Subtracting 20 from both sides we get:

-20 = a(70)^2

Taking the square root of both sides:

sqrt(-20) = a(70)

Dividing both sides by 70:

-sqrt(20)/70 = a

a = -sqrt(20)/70

So the value of a is -sqrt(20)/70