here:
Transformations (equations involving the sum of sin and cos / axillary angle method)
asinx + bcosx = rsin(x+α)
asinx - bcosx = rsin(x-α)
acosx - bsinx = rcos(x+α)
acosx + bsinx = rcos(x-α) Where:
r = √(a<sup>2</sup> + b<sup>2</sup>)
α is in the first quadrant such that tanα =...
II) x double dot = -4(x-3)
there for n^2 = 4
n = 2
therre fore period = 2pi/2
= pi
iii) i would use auxilary angle method on x then differentiate
iv) let xdot = 2 and work it out
edit: should put xdot = plus or minus 2
also, use your reading time effectively, look at the harder section of the test questions 6-8 and decide which questions you are more confident with, i.e you can score the most marks in and do those first, and do the ones your less confident with after