Answer:
The position is given by r(t) = (-2 -t √14, 1 + √3.5, 3 + 3√3.5)
Step-by-step explanation:
The direction is given by the difference between the starting point and the end point, thus it is (-4,0,6)-(-2,-1,3) = (-2,1,3). The norm of this vector is √( (-2)²+1²+3²) = √14 = 3.7416 secons
Since the speed is 7 cm/sec, we need to multiply this vector by 7/√14 = √3.5 in order to obtain how much does the particle advance each second.
As a consecuence, it advances (-2,1,3) * √3.5 = (- √14, √3.5, 3 √3.5)
And, as a result, the position after t seconds is given by the function
r(t) = (-2,1,3) + t (-√14, √3.5, 3 √3.5) = (-2 -t √14, 1 + √3.5, 3 + 3√3.5)