Hi, I need help with these questions. I have to write a trig function equation for the following:

If you could just help me and show me how to get started with any one of them, that would be appreciated so that I can get started and work on the others myself. Thanks!

6. As the paddlewheel turned, a point on the paddle blade moved back in such a way that its distance, d, from the water's surface was a sinusoidal function of time. When a stopwatch read 4 seconds the point was at it's highest, 16ft about the water's surface. The wheel's diameter was 18 ft. and it completed a revolution every 10 second.

7. The number of sunspots counted in a given year varies periodically from a minimum of about 1 per year to about 110 per year. Between the maximums that occurred in the years 1750 and 1948, there were 18 complete cycles.

8. You seek treasure that is buried in the side of a mountain. The mountain range is a sinusoidal cross section. The valley to the left is filled with water to a depth of 50 meter, and the top of the range is 150 meters above water level. You set up an x-axis at water level and a y axis 200 meters to the right of the deepest part of the water. The top of the mountain is at x=400 meter.

9. A creatures body temperature is varying sinusoidally with time. 35 minutes after they start timing it reaches a high of 120 degrees F and a 20 minutes after that its next low is 104 degrees F.