A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

Help with a trigonometric question, please! It's posted in the comments.

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

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

    @misty1212

  3. jdoe0001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    \(\bf 0<\theta<90^o\textit{means the 1st quadrant, means sine and cosine are both positive} \\ \quad \\ sin(\theta)=\cfrac{21}{29}\qquad sin(\theta)=\cfrac{opposite}{hypotenuse}\qquad thus \\ \quad \\ sin(\theta)=\cfrac{21}{29}\to \cfrac{opposite}{hypotenuse}\to \cfrac{b}{c}\to \cfrac{b=21}{c=29} \\ \quad \\ \textit{using the pythagorean theorem }\to c^2=a^2+b^2\implies \pm\sqrt{c^2-b^2}=a \\ \quad \\ \pm\sqrt{29^2-21^2}=a\) what would that give youu for "a" then? recall "a" = "adjacent side"|dw:1435102900196:dw|

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

    a=20

  5. jdoe0001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    yeap so now we know that the adjacent side is 20 notice that, the root could give a -20 or a +20, so it couild really be either because either one squared, will give 400 anyway BUT, we know the angle is in the 1st quadrant, and on the 1st quadrant, cosine is positive and also is the adjacent side, thus we'll use the +20 then thus \(\bf cos(\theta)=\cfrac{adjacent}{hypotenuse}\to \cfrac{a}{c}\to \cfrac{20}{29}\)

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

    So the answer is C. Thanks! It was really easy to follow you and understand what you were trying to explain.

  7. jdoe0001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    :)

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

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

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.