Quantcast

Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

mags093

Could anyone help with this? i got as far as sqrt(4) * sin[coz^-1(sqrt(4)/ 2sqrt(22)] but its wrong? Find the distance the point P(1,5,5) is to the line through the two points Q(1,2,5), and R(4,4,2).

  • one year ago
  • one year ago

  • This Question is Closed
  1. amistre64
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1359730906752:dw|

    • one year ago
  2. amistre64
    Best Response
    You've already chosen the best response.
    Medals 0

    \[cos\alpha=\frac{u.v}{|u|~|v|}\] \[\alpha=cos^{-1}\frac{u.v}{|u|~|v|}\] \[PQ~sin~\alpha=PQ~cos^{-1}\frac{u.v}{|u|~|v|}\]

    • one year ago
  3. mags093
    Best Response
    You've already chosen the best response.
    Medals 0

    i had this formula: [((sqrt(a-d)^2 +(b-e)^2+(c-f)^2 * sin(c0s^-1([(a-d)g + (b-e)h + (c-f)i] / sqrt(a-d)^2 +(b-e)^2+(c-f)^2 sqrtg^2+h^2=i^2]))

    • one year ago
  4. amistre64
    Best Response
    You've already chosen the best response.
    Medals 0

    i never remember formulas to well so I tend to have to reconstruct a method that will work out :) that was the simplest one I could manufacture :)

    • one year ago
  5. mags093
    Best Response
    You've already chosen the best response.
    Medals 0

    i dont understand your method as we did the other one! could you show me how to use yours?

    • one year ago
  6. amistre64
    Best Response
    You've already chosen the best response.
    Medals 0

    I know the basic formula to fine the angle between QR and PQ, i know that the distance is a perp line value from P to R; which is equal to the hypotenuse times the sine of the angle. P(1,5,5) -Q(1,2,5) -------- <0,3,0>; PQ = 3 Q(1,2,5) -R(4,4,2). ---------- <-3,-2,3>; QR = sqrt(22) im curious if they gave us a rt triangle to begin with now :)

    • one year ago
  7. amistre64
    Best Response
    You've already chosen the best response.
    Medals 0

    P(1,5,5) -R(4,4,2) --------- <-3,1,3> <0,3,0>pq <-3,-2,3>qr <-3,1,3>pr <-3,1,3>pr ---------------------- 0+3+0 9+9-2 <0,3,0>pq <-3,-2,3>qr ------------ 0-6+0 nope, nothings at right angles to begin with :)

    • one year ago
  8. amistre64
    Best Response
    You've already chosen the best response.
    Medals 0

    \[3~cos^{-1}\frac{-6}{3\sqrt{22}}=abt~6.034\] is the distance from the line to the given point.

    • one year ago
  9. amistre64
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1359731838243:dw|

    • one year ago
  10. mags093
    Best Response
    You've already chosen the best response.
    Medals 0

    so it should be 3sqrt22 not 2sqrt22?

    • one year ago
    • Attachments:

See more questions >>>

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
  • 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.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.