I'm studying electrical engineering at WING and I don't understand this task. Can someone explain it to me and show me step by step what I need to do?

Basically, you need to know (and apply) that the current is equal to the time rate of change of the charge.

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(a)

You have the equation

for the electrical charge. The current intensity is now equal to the time rate of change (time derivative) of the charge. So you must first derive the function Q ( t ).

[See, for example,: https://de.wikipedia.org/wiki/Electric_powerstrength#Supplements,_the_to_Definition_used_can_be used )

In the concrete case, you get…

From the function graph shown, the amplitude can be

and the period

read the time course of the electrical charge. If this is used in the function equation for the current intensity, then…

For the course of the current

with a current amplitude

(b)