A community for students.
Here's the question you clicked on:
 0 viewing
anonymous
 3 years ago
Question:
a) Let P and Q be two points in space, and X the midpoint of the line segment PQ.
Let O be an arbitrary ﬁxed point; show that as vectors, OX = 1/2 (OP + OQ) .
b) With the notation of part (a), assume that X divides the line segment PQ in
the ratio r : s, where r + s = 1. Derive an expression for OX in terms of OP and OQ.
Answer:
a) OX = OP + PX = OP + 1/2(PQ) = OP + 1/2(OQ−OP)= 1/2(OP + OQ)
b) OX = sOP + rOQ; replace 1/2 by r in above; use 1 − r = s.
My Question: In the answer to part b, what does "replace 1/2 by r in above; use 1 − r = s" mean? How does it help?
anonymous
 3 years ago
Question: a) Let P and Q be two points in space, and X the midpoint of the line segment PQ. Let O be an arbitrary ﬁxed point; show that as vectors, OX = 1/2 (OP + OQ) . b) With the notation of part (a), assume that X divides the line segment PQ in the ratio r : s, where r + s = 1. Derive an expression for OX in terms of OP and OQ. Answer: a) OX = OP + PX = OP + 1/2(PQ) = OP + 1/2(OQ−OP)= 1/2(OP + OQ) b) OX = sOP + rOQ; replace 1/2 by r in above; use 1 − r = s. My Question: In the answer to part b, what does "replace 1/2 by r in above; use 1 − r = s" mean? How does it help?

This Question is Closed
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.