Sounds funny, my name is Andrzej (English = Andrew), but OK.
---> i(t)= is a traingular wave representing current.
it is periodic with period 5ns.
it has a duty cycle of 50%,with A(general) as its amplitude.
I do not know the definition of triangle duty cycle.
(What I know is the square waferorm duty cycle).
But this definitoin it is not a problem (at the moment).
--->if i integrate this waveform ,yes i will get a square wave represeting charge in coulomb.corect sir?.
In my opinion NO.
If at time t=0 the triangle current = 0 and starts to rise it can be described as : I is proportional to time . ie using math symbols y=x (if necessary you can add a coefficent A in front of X )
After integration y= X you will get (x to power 2) / 2
If you integrate the triangle , there is no simple formula for integration, and you shud calculate each part of triangle separately.
0-Max, Max - 0, 0- minus Max (= min) , -Max to 0
integration from 0 to triangle max = 1/4 of full period is parabolic (x^2 / 2).
For next 3 parts (you must integrate the full triangle) you should add 3 parabolas "upside down" and "mirored".
All 4 parabolas (for full period), will form something similar to sin
( but it only looks like sin in fact the curve shape consists of 4 pices of parabola).
May be it help you to solve the problem.