5 10
12 x
Cross multiply = (10 × 12) / 5 =
= 24 days
6/8 because she painted half of her room in 3/4 of an hour and add half of that and you get 6/8! Hope this helps! Im not very good at math so don't judge me if its wrong...
Critical points is where the derivative (slope) is zero or does not exist. So to do this we have to find the derivative of our function:

So we apply chain rule:
=

Set our first derivative to zero and solve for x:
3(x^2 - 1) * 2x = 0
So we can see that (by plugging in) 0, -1 and 1 makes our solution true
So our critical value is x = 0, x = -1, x = 1
The answer is 304.8 millimetres
Using the cosine function:

Solve for b: