/sci/ - Science & Math

Try to do it yourself first.

>>5428115
i cant even think of a first step

ok, i subbed in for the power series of sin k and have cancelled down to
lim(as k tends to infinity) ( sum (from i to infinity) ((k+1)/k)^2i+1

please guys i really need this

>>5428177
Don't assume it converges.

>>5428177
Also I don't know how you got that, but what you did to get it is probably wrong. Dividing the power series shouldn't get you anywhere.

>>5428364
ok, maybe ive gone wrong even earlier

the question was to find the radius of convergence for this power series

>>5428377
pic wouldnt attach for some reason

>>5428377
You're definitely not going to get any help if you can't clearly explain what question you're working on.

>>5428390
the picture hadnt been selected when i thought it had.
if you had seen the picture, i just went from were i was stuck to save time. finding the limit described originally was the problem

>>5428385
Oh, I see what you're doing. The sin(k) part is just a number of size comparable to one no matter how large you make k, so it's not very important in the problem. The terms you have to watch are the x^k, the 6^k and the k^3. Ask first which wins out (making the terms ever larger or ever smaller) and then, if the terms do get smaller, whether they converge to a sum.

No, no, no, no, no, no, no, no, no ,no ,no, no there's no limit!
No, no, no, no, no, no, no, no, no ,no ,no, no there's no limit!

>>5428464

>>5428439
so do i do the limit test at all? because when i do that you can pull mod(x/6) out and the ((K+1)/k)^3 tends to 1 and im just left with the sin(k+1)/sin(k) part?