First off i'd like to say Hi to the forums, hehe. I didn't really see a new member area but I suppose this will do. Right now I'm kind of struggling with these two problems that I recently took a quiz on and didn't do so well. I've been trying to figure out how to work them out but i just dont really get it. if anyone could help out it'd be awesome. (1) The position (in cm) of a particle along the x-axis at time t(in s) is given by X(t) = t^3-6t^2+8t, t is greater than or equal to 0. the question: When is the particle moving to the left? the right? Acceleration of the particle when the speed is zero. Total distance traveled from t=0 to t=2. (2) ( and the one that REALLY gets me) A person standing 30ft from the base of a building measures the angle of elevation to the top of the building as being 75 degrees with an error of +or- 1.2 degrees. What is the max error in estimating the height of the building, and the percentage error? This one has taken me quite a while, I am thinking it has something to do with the law of sines, but when i try it with that method i'm getting a completely unreasonable answer. I kind of have the right idea, i hope, but for some reason i'm just not seeing it. Thank you in advance for those who wish to take on these.