Let P = (4, 3, −3) and Q = (6, 7, 7). Find the coordinates of the following. The point on the line through PQ whose distance from P is twice its distance from Q and which does not lie between these two points.

Respuesta :

Answer:

Our point is (16/3,17/3,11/3)

Step-by-step explanation:

We will need to find a point in line that goes  though P and Q.

To find this line we will need a point in the line (which can be P or Q) and a poiting vector V. This vector can be found subtracting P and Q. V=Q-P

V=(6, 7, 7) - (4, 3, −3)= (2,4,10)

the parametric equation r(t) = P+V*t for the line where will replace out values P and V:

r(t)=(4, 3, −3)+r*(2,4,10) our new point must fulfill this equation for a given t

On the other hand out point A must fulfill that the distance from P is twice its distance from Q.

If we choose a point in between the points and call the distance between P and Q  1, A must be 1/3 of the way to Q and 2/3 of the way to P.

Since the starting point for our parametric equation is P, replacing r for 2/3 on the parametric equation will give us a point r(2/3) that is in the line and is twice as far from P than it is from Q

A=r(2/3)=(4, 3, −3)+2/3*(2,4,10)=(16/3,17/3,11/3)