The fluctuation of water depth at a pier is shown in the
figure below. One of the following values gives the
positive difference, in feet, between the greatest water
depth and the least water depth shown in this graph.
Which value is it?

Asmall (but heavy) particle placed in a glass of water will follow a zigzag motion because the particle will bounce off of the water molecules it meets. this is called brownian motion. a physicist simulates this on a computer, by varying the distance a particle can travel (called the mean free length), on average, before it collides with a water molecule and assigning the change in motion to be one of 8 directions, each with a similar probability. by running the simulated particle (with the same mean free length) many times she determines that it should take 15 seconds, on average, for the particle to fall to the bottom, with a standard deviation of 1.5 seconds. next she lets a real particle fall through a glass of water and finds that it took 18 seconds. what does she conclude, and why?

Answer for 10 points show work you guys in advanced < 3

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.