<u>Answer:</u>
Speed of the boat in still water = 6.125 miles/hour
<u>Step-by-step explanation:</u>
We are given that a boat travels 33 miles downstream in 4 hours and the return trip takes the boat 7 hours.
We are to find the speed of the boat in the still water.
Assuming
to be the speed of the boat in still water and
to be the speed of the water.
The speeds of the boat add up when the boat and water travel in the same direction.


And the speed of the water is subtracted from the speed of the boat when the boat is moving upstream.

Adding the two equations to get:

+ 
___________________________

Solving this equation for
and substituting the given values for
:




Therefore, the speed of the boat in still water is 6.125 miles/hour.
as you already know, the slope of the tangent line is simply the derivative of the function, so
![r=2cos(3\theta )\implies \cfrac{dr}{d\theta }=2\stackrel{chain~rule}{\left[ -sin(3\theta )\cdot 3 \right]} \\\\\\ \left. \cfrac{dr}{d\theta }=-6sin(3\theta ) \right|_{\theta =\frac{\pi }{6}}\implies -6sin\left( 3\cdot \frac{\pi }{6} \right)\implies -6sin\left( \frac{\pi }{2} \right)\implies -6](https://tex.z-dn.net/?f=r%3D2cos%283%5Ctheta%20%29%5Cimplies%20%5Ccfrac%7Bdr%7D%7Bd%5Ctheta%20%7D%3D2%5Cstackrel%7Bchain~rule%7D%7B%5Cleft%5B%20-sin%283%5Ctheta%20%29%5Ccdot%203%20%5Cright%5D%7D%20%5C%5C%5C%5C%5C%5C%20%5Cleft.%20%5Ccfrac%7Bdr%7D%7Bd%5Ctheta%20%7D%3D-6sin%283%5Ctheta%20%29%20%5Cright%7C_%7B%5Ctheta%20%3D%5Cfrac%7B%5Cpi%20%7D%7B6%7D%7D%5Cimplies%20-6sin%5Cleft%28%203%5Ccdot%20%5Cfrac%7B%5Cpi%20%7D%7B6%7D%20%5Cright%29%5Cimplies%20-6sin%5Cleft%28%20%5Cfrac%7B%5Cpi%20%7D%7B2%7D%20%5Cright%29%5Cimplies%20-6)
33.3 would be the correct answer of 74% of 45
Answer:
A
Step-by-step explanation:
Rectangular Pyramid
Which one first show me your problem