A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 4 years ago

Express each of the following in terms of a reference angle. Explain, please. 1a. sin 45º 1b. 135º 1c. sin 225º 1d. sin 315º 3a. cos 224.5º 3b. cos 658º 3c. 145.7º 3d. sin (-201º)

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

    what is reference angle for you?

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

    I'm not really sure... I think that's the problem.

  3. Mertsj
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    The reference angle is the angle the terminal side of the angle makes with the x axis.

  4. Mertsj
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1328586602494:dw|

  5. Mertsj
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1328586699401:dw|

  6. Mertsj
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1328586836262:dw|

  7. Mertsj
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    But you have to be careful about your signs. For example the sin225=-sin45 because the sin (which is like y) is positive in the first quadrant but negative in the 3rd and 4th quadrants.

  8. Mertsj
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    sin135=sin45 since sin is positive in quadrants 1 and 2

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

    All-Sine-Tan-Cos

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

    and in simple terms the reference angle is the acute version of the angle.

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

    So, for instance, number 1a, I'd just find the sine of 45º because the reference angle of 45 º is 45º, right? And for number 1b, 135º's reference angle is 45º degrees as well, so i'd find the sine of 45º... I guess I still don't fully understand how to know whether its positive or negative. In the pictures, would it be positive or negative based on where the degree of a circle ended? Sorry if I'm a little slow! I'm only in eighth grade, but i'm taking classes at the university:/

  12. 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.