Question

A point has a position vector given by r of t equals the vector with components t squared, 4 minus , t for all time t ≥ 0 seconds. Find the speed of the object at t = 1 seconds. (10 points)
A) 1
B) 5
C) 2
D) square root of 5

Answer 1

why not just say r(t) = <t^2,-4,t>
then you have
v(t) = <2t,0,1>
v(1) = <2,0,1>
so the speed is just |v(1)|

Answer 2

sorry i wrote it wrong it is, r(t) =( t^2+1,4-t). Everything else remains the same. Please help