Answer:
its red
Step-by-step explanation:
math. lol
<span>Triangle ACD is similar to triangle ABD</span>
A function

is periodic if there is some constant

such that

for all

in the domain of

. Then

is the "period" of

.
Example:
If

, then we have

, and so

is periodic with period

.
It gets a bit more complicated for a function like yours. We're looking for

such that

Expanding on the left, you have

and

It follows that the following must be satisfied:

The first two equations are satisfied whenever

, or more generally, when

and

(i.e. any multiple of 4).
The second two are satisfied whenever

, and more generally when

with

(any multiple of 10/7).
It then follows that all four equations will be satisfied whenever the two sets above intersect. This happens when

is any common multiple of 4 and 10/7. The least positive one would be 20, which means the period for your function is 20.
Let's verify:


More generally, it can be shown that

is periodic with period

.
I think it'd be 9 seconds, not 100% sure though.
Answer:
Step-by-step explanation:
0.75 feet / day [ 1 day / 24 hours] * [12 inches / 1 foot]
This process is called dimensional analysis. The trick it uses is to cancel out units (like feet or days ) where possible. In this case, 1 day is going to cancel out and leave behind 24 hours. 1 foot will cancel out and leave behind 12 inches.
It is well worth learning how to do this, because the process is done in the higher sciences.
So what you are left with is
0.75 * 12 inches / 24 hours
0.75 inches /hour * 1/2
0.375 inches / hour.