Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

bridgetx516x

  • 3 years ago

Find cos(x+y) for cos x =-4/5 ans sin y = 5/13 with x and y being in quadrant 2.

  • This Question is Closed
  1. bridgetx516x
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    this is what i have got so far..|dw:1364147163106:dw|

  2. bridgetx516x
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    that would give me an answer of .9995 which is not an option a. .51 b. .97 c. -.51 d. -1.72 e. None of the above. is the answer E or have I done something wrong?

  3. harsimran_hs4
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    no answer is not e you have applied totally wrong concept cos(x + y) where x and y are angles x is not -4/5 but cos x = -4/5 use : cos(x + y) = (cosx)*(cosy) - (sinx) * (siny)

  4. bridgetx516x
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i just tried that and still didnt get and an answer. I did: cos(-4/5) Cos(-12/13) - sin(3/5) sin(5/13) (.99)(.99)- (.01)(.006) (.99)-(.00007) = .999702 @harsimran_hs4

  5. harsimran_hs4
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    you are doing the same mistake please have a look at the above comment MIND IT: X IS ANGLE AND NOT -4/5 COS X = -4/5

  6. bridgetx516x
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh alright. but i did it and got -.97 and an answer

  7. bridgetx516x
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    just kidding I got .51

  8. harsimran_hs4
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    so you are done or still any doubt?

  9. bridgetx516x
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yes i am, thank you!

  10. harsimran_hs4
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    cool :)

  11. 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