Ok so i have the next exercise.
I didn't had any problems solving a) and b)
What about c?
Can anyone tell me how to resolve it?
I googled it and found out that's Si(x)(whatever that is) and i don't know about what's that since i'm just last grade of high school.
In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.
You may use taylor expansion about t=0 for c)
"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?
"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."