*In a scene from "The Martian" Matt Damon shoots a flare straight up into the sky. The

height (in feet) of the flare after t seconds is

given by

s(t) = -3t? + 100t +3

What is the velocity of the flare when it is

moving toward the ground and its position is

equal to 131 feet?

(

The velocity is 4.094ft/s

Step-by-step explanation:

Given

Required

Find the velocity at 131ft

First, calculate the time taken to reach 131 ft

This gives:

Rewrite as:

Expand

Factorize

Factor out t - 32

Split

Solve for t

Since 32 > 4/3, then the flare is going up at 4/3s and coming down at 32s

The velocity is calculated as:

So, we have:

4 and 5)16.97 or 12√2

6)15.59 or 9√3

7)y = 15.59 or 9√3     x =27

8)17.80

hello from mrbilldoesmath!

answer:   x (x+6)^2, choice b

discussion:

factor x out of the equation:

x^3 + 12x^2 + 36x = x (x^2 + 12x + 36).

note that 6+6 = 12 and 6*6 = 36 so the above factors into:

x (x+6)^2

which is choice b

you,

mrb