# Math Help - vector calculus

1. ## vector calculus

∫a.da dt
dt

if a(2)=2i-j+2k
a(3)= 4i-2j+3k

the limits on the intergral should be 3 and 2 and it should be da/dt

aprently the answer is 10 but i cant see how to do it
help appreciated thanks

2. a.da/dt dt

3. Originally Posted by smile!
∫a.da dt
dt

if a(2)=2i-j+2k
a(3)= 4i-2j+3k

the limits on the intergral should be 3 and 2 and it should be da/dt

aprently the answer is 10 but i cant see how to do it
help appreciated thanks
it is a substitution problem in disguise

make a substitution, $u = a$

the result follows

Hint: differentiating implicitly we find that $\frac {du}{dt} = \frac {da}{dt}$