Answer:
Part 1) 
Part 2) 
Part 3) 
Step-by-step explanation:
Part 1) Find AC
we know that
In the right triangle ABC of the figure
Applying the Pythagorean Theorem

substitute the given values


Part 2) Find the measure of angle A
we know that
In the right triangle ABC
----> by TOA (opposite side divided by the adjacent side)
substitute the values

using a calculator

Part 3) Find the measure of angle C
we know that
In the right triangle ABC
----> by complementary angles
substitute the given value


<span>A medical researcher wants to investigate the amount of time it takes for patients' headache pain to be relieved after taking a new prescription painkiller. She plans to use statistical methods to estimate the mean of the population of relief times. She believes that the population is normally distributed with a standard deviation of 18 minutes. How large a sample should she take to estimate the mean time to within 4 minutes with 97% confidence?
-----
n = [z*s/E]^2
---
n = [2.17*18/4]^2 = 96 when rounded up
</span>
Answer:
The result is about 70.9 degrees
Step-by-step explanation:
Easy for a calculator. If you're not using a calculator, it's much more tedious!
There is an inverse sine key on your calculator, but you may have to press a key (likely labeled 2nd or INV) first. The attached image shows a TI-83 display. To get the inverse sine, I first pressed the yellow 2nd key, then the sin key.
Check MODE first to make sure you're measuring angles in degrees (if that's what you want!). Some calculators display angle mode with a small letter at the top of the display, D, R, or G usually.
The left side of the equation produces just x.

<span>10 seconds.
You need to figure out when the height of the bolt reaches 0. Given the equation:
1600 - 16T^2 = 0
Add 16T^2 to both sides
1600 = 16T^2
Divide both sides by 16
100 = T^2
Take the square root of both sides
10 = T
Therefore the bolt will hit the ground after 10 seconds.</span>
Answer:
X = 5
Step-by-step explanation:
3x + 12 + 9x = 72
okay hopefully i can explain so when your doing this combine like terms so
3x + 9x = 12x
12x + 12 = 72
then you would subtract both sides by 12
+12 = subtract x+12=2
- 12 = add x-12=2
there just flipped so in this case i would subtract 12
12x + ( 12-12) = ( 72-12 )
so 12-12 = 0 and 72-12 is equal to 60
12x = 60
the divide on both sides l but leave the x alone so its just 60 divided by 12 wich is 5
so X = 5
hope this helps with ur homework a little btw go back and redo ur other awnsers with this new concept hope it helps