The vector a depends on a parameter t, i.e. .. it satisfies the equation

show that , and .

For the vector a, find its value for t=pi if at t=0 and

i have absolutely no idea how to start...

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- January 8th 2010, 06:29 AMEmma Lvectors and differentiation
The vector a depends on a parameter t, i.e. .. it satisfies the equation

show that , and .

For the vector a, find its value for t=pi if at t=0 and

i have absolutely no idea how to start... - January 8th 2010, 08:14 AMShanks
can you use latex to restate your problem?

- January 9th 2010, 03:16 PMEmma L
Hope that's a bit clearer :) sorry, wasnt sure how to do the vector product in latex(Doh)

- January 9th 2010, 03:20 PMDrexel28
- January 9th 2010, 04:21 PMEmma L
ye sorry, it's the cross product

- January 10th 2010, 07:00 AMHallsofIvy
So the problem is that you are given such that and you are asked to show that, in that case, , , and .

Okay, go ahead and calculate . That's easy, it is just . Setting equal to that gives you three equations: , , and .

differentiating the first of those, with respect to t, gives . Get the point? I'll leave the others to you now.

For the last part you need to solve those equations. is easy: is a constant and the last part tells us that that constant is 1.

To solve the other two, use the fact, that you have now shown, that and . Solve those differential equations using the initial values , , , and .