Quantcast

A community for students. Sign up today!

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

yanni

  • one year ago

i neeeed serious help.....

  • This Question is Closed
  1. Chelsea04
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    what do you need help with?

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

    In the figure below, find the exact value of y. (Do not approximate your answer.)

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

    i attached the problem

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

    find the side of the larger triange, using pyth theorem

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

    Okay. It is a 45 45 90 triangle. So we know the hypotenuse is five. The hypotenuse in a 45 45 90 triangle is x(sqrt2). So sqrt2 is 1.41. 5/1.41 is 3.546. So x=3.546. Since it equals x.

  6. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    The three triangles are similar, so the lengths of their sides are proportional. 6/5 = 5/y

  7. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    You don't know it's a 45-45-90 triangle.

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

    then the side that you found is the hypothenuse of 45-45-90 triangle. using that hypotheneuse is twice as large as legs, find the size of the legs

  9. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    If the altitude is drawn to the hypotenuse of a right triangle, each leg of the right triangle is the geometric mean of the hypotenuse and the segment of the hypotenuse adjacent to the leg.

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

    simple - use 45-45-90 logic that y -y - ysqrt2 5 = ysqrt2 solve for y

  11. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @JuanitaM Why do you keep mentioning a 45-45-90 trianlge when we don't have one here?

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

    yes an altitude was droppened to form 90 degree at base labeled 6

  13. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    The large triangle has hypotenuse of length 6 and a leg of length 5. The other leg cannot possibly measure 5, so it's not a 45-45-90 triangle. Since all triangles are similar, none of them are 45-45-90 triangles.

  14. Chelsea04
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Find the 3rd side of the triangle, label this x. \[x=\sqrt{6^2-5^2}=\sqrt{11}\] Then find the line going straight down the triangle, label this z. You can do this two ways (you'll need both ways). \[z=\sqrt{\sqrt{11}^2-(6-y)^2}=\sqrt{11-(6-y)^2}\] \[z=\sqrt{5^2-y^2}\] If you make them equal to each other, you'll be able to solve for y. \[\sqrt{11-(6-y)^2}=\sqrt{5^2-y^2}\] \[11-(6-y)^2=25-y^2\] \[11-(36-12y+y^2)=25-y^2\] \[2y^2-12y-50=0\] \[\therefore y=\sqrt{34}+3\]

  15. Chelsea04
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Is this too confusing?

  16. Chelsea04
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1360214471836:dw| Maybe that will make it more understandable :)

  17. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @Chelsea04 Can you try to calculate your answer for y as a number rounded off to the nearest tenth?

  18. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @yanni Did you understand anything about this problem or are you more confused than when you asked the question?

  19. agent0smith
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Chelsea, your answer cannot be correct. Your value of y is greater than the 6 at the base of the triangle!

  20. agent0smith
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Chelsea, this is your mistake: \[11−(36−12y+y^2)=25−y^2\]\[12y−50=0 \] mathstudent55 has the correct answer: The three triangles are similar, so the lengths of their sides are proportional. 6/5 = 5/y You can confirm it by using cosine.

  21. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @agent0smith Finally a voice of reason. Thanks!

  22. agent0smith
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    haha no prob. I forgot to make the drawing:

  23. agent0smith
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    I'll call that angle x |dw:1360216763172:dw| First, look at the bigger/outer triangle \[\cos x = \frac{ 5 }{ 6 }\] Now, look at the inner triangle: \[\cos x = \frac{ y }{ 5 }\] |dw:1360216959551:dw|

  24. Chelsea04
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Right, oops!!! That seems like a much faster way!!!

  25. agent0smith
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    once you get cosx = 5/6 and cos x = y/5, then you can equate 5/6 = y/5

  26. Chelsea04
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Either way is correct, just mine was more algebraic (and a little wrong!) than trignometric.

  27. agent0smith
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Yes, your way works (other than your mistake) but will probably take longer.

  28. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Ask a Question
Find 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
  • 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.