Hello, I am in grade 12 taking math31 which is pretty much a college course. Im not doing that great in it at the moment and I just found this forum with less than 2 months left in the semester. Anyway, there are a few questions I am stuck on. One of them is: (note: all of the '<' are less than or equal to) 1. Solve for x algebraically in the interval 0<x<2pi sin2x + 4sinx = cosx + 2 2. If sin(a)=8/17 , 0<a<pi/2 and tan(b)=7/24 , pi<b<3pi/2, find cos(a-b) 3. A balloon rises at the rate of 3m/s from a point 50m from an observer. Find the rate of change of the angle of elevation of the balloon from the observer when the balloon is 30m above the ground? Thanks very much!