Recall the double angle identity:

With
measuring between 0º and 90º, we know
. So from the Pythagorean identity, we get

Then

Answer:
Step-by-step explanation:
I see you're in college math, so we'll solve this with calculus, since it's the easiest way anyway.
The position equation is
That equation will give us the height of the rock at ANY TIME during its travels. I could find the height at 2 seconds by plugging in a 2 for t; I could find the height at 12 seconds by plugging in a 12 for t, etc.
The first derivative of position is velocity:
v(t) = -3.72t + 15 and you stated that the rock will be at its max height when the velocity is 0, so we plug in a 0 for v(t):
0 = -3.72t + 15 and solve for t:\
-15 = -3.72t so
t = 4.03 seconds. This is how long it takes to get to its max height. Knowing that, we can plug 4.03 seconds into the position equation to find the height at 4.03 seconds:
s(4.03) = -1.86(4.03)² + 15(4.03) so
s(4.03) = 30.2 meters.
Calculus is amazing. Much easier than most methods to solve problems like this.
Answer:
<em>Lisa borrowed $8,500</em>
Step-by-step explanation:
<u>Simple Interest
</u>
Occurs when the interest is calculated on the original principal of a loan only.
Unlike compound interest where the interest earned in the compounding periods is added to the old principal, simple interest only considers the principal to calculate the interest.
The interest earned is calculated as follows:
I=Prt
Where:
I = Interest
P = initial principal balance
r = interest rate
t = time
Lisa took out a loan for t=5 months and was charged simple interest at an annual rate of r=4.8% = 0.048. She paid interest for I=$170.
We need to convert the time to years (there are 12 months per year):
t = 5 /12 years.
The formula must be solved for P:

Substituting:


Lisa borrowed $8,500
Answer:
It's the second one. Press 'Ask For Help' if you need more help on problems