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楼主还真幽默

oh I made a mistake there.. 26.25 - 15 is 11.25 not 11.5 my bad.. Anyway, the main purpose of that post was to show that one can use the familiar idea of energy from physics.

let R = sqrt(a^2 + b^2) x = R [ (a/R)sin(nt) + (b/R)cos(nt)] recognise that a,b,R form a right angled triangle, so a/R = sin(w) and b = cos(w) for some angle w = arcsin(a/R) so can rewrite x = R(sin(w)sin(nt) + cos(w)cos(nt)) = R(cos(nt - w)) should be easier now I hope beh upstairs beat me...

so erm.. which particular subjects do you have so far

In maths if you aren't given g then you write g as g.

From the question we know that at some particular time T , y'(T) = 0, y(T) = 26.5 and x(T) = 30 1. show that [(y')^2 / 2] + gy is constant 2. from that we can deduce that y'(0) = sqrt(2*11.25*g) = sqrt(22.5g) 3. ofcourse y'(t) = y'(0) - gt, so in particular, 0=y'(T) = y'(0) - gT so T = y'(0)/g...

look up devil's staircase for something just as interesting. it is also probably possible to construct a continuous function which is differentiable almost nowhere.

35/36 (you just need 1 even number) (6 choose 2) (1/6)^2 (1/2)^4 (pick where the 6 goes then multiply the probabilities) 1/6 * (5 choose 3)(1/2)^3 (1/3)^2

generally yes and yes... you should call the university administration though.

collective myopia and politics drives any process.

method 1: find the equation of a tangent and the perpendicular, solve, etc. (this is the usual way) dy/dx = dy/dy / dx/dt = -1/t^2 so the tangent is (y - c/t) = -(x - ct)/t^2 -------> x + yt^2 =2ct and the perpendicular has gradient t^2 through the origin, so its formula is y = t^2 x...

no, you can try for internships after first year though... how many actuaries do you think they need?

then you go lim [h-> 0] |f(a+h)-f(h)| = lim [h -> 0] |f(h)| = 0 so f is continuous at a. or even without hte absolute value signs

oh you used running averages which is technically more correct :P

FOB delivery point means the buyer bears the costs... I thought that would be called FOB or FOB shipping point. In any case it's when the title changes. read the question.. it's not asking about the cost of goods sold but about how much the remaining inventory is worth... you calculated cost...

first question: If I understood correctly FOB delivery point means that title changes when it is received and seller pays for freight, so no. second q: FIFO: 8 units are sold and 12 were bought.. so inventory value = cost of last 4 units = 3*106+99 = 417 Average cost: 4 units are left out 12...

1.) differentiate implicitly to get dy/dx = - x/(6y) then solve dy/dx = 0 with x^2 + 6y^2 = 15 which should give you (x,y) = (3,-1) pr (-3,1) etc. 2.) Q2 is easier than Q1, find y then continue.

The correct answer is sin(5.5x)/sin(0.5x)

they do.. it's called the orthocenter you can prove it by some simple circle geometry. Let 2 altitudes intersect at H, consider the line through H and the 3 vertex. prove that this is perpendicular to the corresponding base (there are many cyclic quadrilaterals in this figure)

It is not surprising that proprietary notes contain errors