Find the area of the surface. the part of the hyperbolic paraboloid z = y2 â x2 that lies between the cylinders x2 + y2 = 4 and x2 + y2 = 25.

Acommunity group sells 2,000 tickets for its raffle. the grand prize is a car. neil and 9 of his friends buy 10 tickets each. when the winning ticket number is announced, it is found to belong to neil's group. given this information, what is the probability that the ticket belongs to neil? a.1/5 b.1/10 c.1/200 d.1/4

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?

Through non-collinear points there is exactly one plane.