Question

This is the equation of an arch h=-0.2d^2+3.2

How wide is the arch at the base

Answer 1

How Do I solve this?

Answer 2

I set h = 0 but then I was getting 4 but actually the answer says 8

Answer 3

You are on the right track.
Solve the equation with h = 0.
You get a quadratic with two solutions, \(x_1\) and \(x_2\).
The answer is the distance between those two solutions:
\( | x_1 - x_2 | \)

Answer 4

Do you mind showing?

Answer 5

When you square root something, it is both positive and negative so basically I subtract 4--4 giving me 8 right? @mathstudent55

Answer 6

Square Root of 16 is 4 and - 4 and by subtracting them you get 8 right?

Answer 7

\(h=-0.2d^2+3.2 \)

\(0=-0.2d^2+3.2 \)

\( 0.2d^2 = 3.2 \)

\(d^2 = 16\)

d = 4 or d = -4

|4 - 4| = |8| = 8
or |-4 - 4| = |-8| = 8

Answer 8

Thank you so much

Answer 9

welcm