So, I have r^3=1/64. I need help finding r

1. Use the given info to solve the triangle. C=135degrees, c=45, B=10degrees

2. A 10-meter telephone pole casts a 17-meter shadow directly down a slope when the angle of elevation of the sun is 42degrees. Find the theta, the angle of elevation of the ground.

3. Use the Law of Cosines to solve the triangle. a=75, b=52, c=52

4. On a map, Orlando is 178 mm due south of Niagra Falls, Denver is 273 mm from Orlando, and Denver is 235 mm from Niagra Falls:

a. Find the bearing of Dever from Orlando.

b. Find the bearing of Denver from Niagra Falls.

In problems 2-5, use the given info to solve triangle ABC (if possible). If 2 exist, list both.

2. A=15degrees, a=5, b=10

3. A=43degrees, B=98degrees, c=22

4. B=110degrees, a=4, c=4

5. A=75degrees, a=2.5, b=16.5

6. If a regular octagon is inscribed in a circle with radius 16, what is the length of one side of the octagon?

7. Find the area of triangle ABC if a=4, b=5, and c=7.

8. Let v be the vector with initial point (o, 10) and terminal point (7, 3). Write v as a linear combination of the standard unit vectors i and j.

#96

r=625       theta=pi/2

I found the 4th root of 625....it = 5.

Now, I'm supposed to use DeMoivre's Theorem. Then divide pi/2 by 4 and add k/4 times 2pi with k going between 0 and 3.

The 2nd angle should be 5pi/8, third should be 9pi/8, and the last should be 13pi/8.

((Show me how please. Thanks!))

#30

llvll=3              u=<4,-4>

-Find the magnitude of the given vector and divide each of the components by that magnitude. That will produce a unit vector that is the same direction of the given vector. Since it wants the magnitude to be equal to 3, multiply each component by 3. Make sure the radicans are out of the denominator. The answer should be a vector in component form.

#48

llvll=3            u=3i+4j