(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

The vector a depends on a parameter t, i.e. [itex]a=a(t)=a_x(t)i +a_y(t)j +a_z(t)k[/itex]..

it satisfies the equation [itex]da/dt= j [/itex][tex]\times[/tex][itex] a[/itex]

show that [itex]d^2a_x/dt^2 =-a_x[/itex] , [itex]da_y/dt=0[/itex] and [itex]d^2a_z/dt^2 =-a_z[/itex].

For the vector a, find its value for t=pi if at t=0 [itex]a(0)=i+j[/itex] and [itex]da/dt(0)=0k [/itex]

2. Relevant equations

[itex] a.b = mod(a)mod(b)cos\theta [/itex]

[itex] a [/itex] X [itex] b = mod(a)mod(b)sin\theta[/tex] [tex]\hat{n}[/tex] [/itex]

3. The attempt at a solution

i have absolutely no idea how to start...

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# Homework Help: Vectors and differentiation

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