4.1:
For n=2, obvious.
Suppose true for n=k.
Then consider n=k+1. Consider the graph of P(x). Suppose x=m (m constant) is a multiple zero for n=k+1. (1)
Then that means that x=m is a zero for n=k. (2)
So: From (1), 1+m-m^2/2......+(-1)^k.(m^k/k!)+(-1)^(k+1).(m^(k+1)/(k+1)!)=0 (A)
From...
I usually answer only the hard q's...
but if there's an easy q lying around that no one has answered, why not do that? :-)
For reference, usually I log on say once a day, and by the time I see a q someone has answered it 90% of the time...
So the latter I guess..
Part (b): I'm lazy, so assuming xayma is right...
x^2+x=y-y^2
So x^2+x+y^2-y=0
So (x+0.5)^2+(y-0.5)^2=0.5
So locus is circle on argand diagram with centre (-0.5+0.5i) with radius 1/root(2).
there's a reason why bashing it doesn't work... it's called RSA encryption...
the reason keypad is doing it is because he doesn't realise how short these holidays are...
Short answer: no.
Long answer: No. It all depends on how you define convergent series... there is, after all, no good way to well-define series as there is numbers. (eg you can well-order rationals, but not reals...)
I suppose defining a new series b_n from a_n a convergent series with...
Soln follows, look away ***SPOILER WARNING*** if you want to do it yourself.
Case bash.
Consider n objects, and no. of ways of choosing k of them. Let one of them arbitrarily be called A.
Case 1: A is chosen. Then we have to choose k-1 from the other n-1, hence n-1C(k-1).
Case 2: A isn't...
Probably the best alternative method is spice girl's... Basically, "stretch" the plane in the direction of the y-axis. As you do that, the x-values don't change, so OT and ON remain constant. As a result, as the minor axis of the ellipse lies on the y-axis, you can "stretch" the plane such that...
Umm, spice girl is spicing it up :-)
Probably the other one is easier to understand and apply generally... unless you have an affinity for geometric transformations, ha ha...
see kimmeh...
It's to do with limits as x -> infinity.
y=(x^2)/(x^2-x+2)=1/(1+(1/x)-(2/x^2)) on dividing by the highest factor.
Now observe that 1/x-2/x^2 has roots 0,2. Also, from that it is less than 0 for x < -2 and > 0 for x > 2.
As x goes to infinity, the 2/x^2 term becomes less...
For p congruent to 1 mod 4, k being a generator means that -k is a generator. Hence the result.
Yet to figure out for 3 mod 4, but it's getting late, more later...
Been away for a while.. and usually by the time I get to a post someone else has got a proof for it... gah.
Hmm... didn't work. I don't think it's going to be easy...
I'll figure out something.