Question

Please,help!
Can someone explain how this equation
(2(-L√S Cos[L√S]+Sin[L√S]))/LS;
S=(2k+1)*Pi ⁄ 2*L)^2;k=0,1,2..
can be equal to 2(-1)^k/LS

Answer 1

im sorry,mistake S=( (2k+1)*Pi ⁄ 2*L )^2

Answer 2

?? can you write it in equation??

Answer 3

(2(-L*((2k+1)*pi/2L) Cos[(2k+1)*pi/2]+Sin[(2k+1)*pi/2]))/( L [(2k+1)*pi/2*L]^2
Did you mean like this ?

Answer 4

http://www.codecogs.com/latex/eqneditor.php

Answer 5

I solved it.

Answer 6

congrats ...