@tomleslie 

Hi,

Thanks for your response,

1. "pi" is ratio of circumference to diameter of a circle(Pi). (i edited it)

2. When I used 'b[n]', "n" is index and then 'b[n]' will be use in summation.

3. When I used 'k[n]', "n" is index and then 'k[n]' will be use in summation.

4. I have one unknown function, q(t). (i edited it)

5. Yes, two unknown variables, 'x' and 't'

6. Excusme actually 'b'='w' (I edited it)

n-h-ie.mw