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

Confusionist Group Title

Can someone help me solve this? cos(x^2+45)+tan(4x+90) = sin(3x+120) A step by step would be great.

  • 7 months ago
  • 7 months ago

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

    by solving do you mean proving?

    • 7 months ago
  2. Confusionist Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Yes. :)

    • 7 months ago
  3. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    What methods have been discussed?

    • 7 months ago
  4. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    We are solving for x not proving this. This isn't an identity.

    • 7 months ago
  5. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    Or does it say to disprove or prove?

    • 7 months ago
  6. Confusionist Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Ah yes, my bad. It says solve.

    • 7 months ago
  7. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    Can you tell me what methods in class have been discussed?

    • 7 months ago
  8. Confusionist Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    None, this is from a book with only problems I picked up at barnes and noble. We haven't done this and wont do it for another year or two. I've had no problems with the book up to this point.

    • 7 months ago
  9. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    can you tell me what methods the book has discussed?

    • 7 months ago
  10. Confusionist Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    None. It's a book of only problems. It starts from Geometry and works it's way up in problems.

    • 7 months ago
  11. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    Name of book please

    • 7 months ago
  12. Confusionist Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Math Review for the High School Classroom

    • 7 months ago
  13. Confusionist Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    I looked for it online and can't find it.

    • 7 months ago
  14. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    I didn't see the book. :( So there are no examples?

    • 7 months ago
  15. Confusionist Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    No examples, just questions. :c How did you learn it?

    • 7 months ago
  16. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    Honestly, I don't know without seeing some example or them mentioning some method they want to use.

    • 7 months ago
  17. Confusionist Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Ah, okay. Thanks, anyway. :)

    • 7 months ago
  18. shamil98 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    cos(x^2+45)+tan(4x+90) = sin(3x+120) cos(x^2+45)+sin/cos(4x+90) = sin(3x+120) dividing everything by sin. tan(x^2+45) + sec(4x+90) = 3x + 120 i don't remember trig that well, but you can convert it to this i think.

    • 7 months ago
  19. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    You can't do that... Like you can't divide by the trig part The trig part is a function not a number or variable on its own

    • 7 months ago
  20. shamil98 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    oh

    • 7 months ago
  21. primeralph Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Are the angles in radians or degrees?

    • 7 months ago
  22. primeralph Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    I'll assume degrees for now.

    • 7 months ago
  23. Confusionist Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Degrees, yeah. ^^

    • 7 months ago
  24. hartnn Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    45,90,120 suggest they are in degrees... we can convert sin and cos in tan, like cos A = tan (sqrt (1-A^2)/A) something like this and then use tan A+tan B formula...... but if thats possible, the algebra is going to be very ugly....

    • 7 months ago
  25. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    but @hartnn tan(90) does not exist you were talking about the sum identity for tan right?

    • 7 months ago
  26. primeralph Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    @myininaya tan(a+90) = -1/tan(a), since they're perpendicular.

    • 7 months ago
  27. hartnn Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    not tan(A+B) tan A +tan B , where B = 4x+90 and yeah, tan (A+90) = - cot 90 so maybe convert cos into cot and use cotA-cotB formula... i don't think that will be of any use though....

    • 7 months ago
  28. primeralph Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1388481204906:dw|

    • 7 months ago
  29. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    I don't like the x squared part much.

    • 7 months ago
  30. primeralph Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Series solution is what I'd prefer to us,e but not without an attempt with standard algera.

    • 7 months ago
  31. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    or maybe the whole problem i don't see how to do it with algebra/trig He said it was for high school though

    • 7 months ago
  32. hartnn Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    even wolf doesn't give integral or rational solutions...

    • 7 months ago
  33. Confusionist Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Yes, I'm a junior in high school, but the book said High School. It extends way past what I expect to learn in High School, though. I think they may have the age range a bit messed up.

    • 7 months ago
  34. primeralph Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    No simple way to solve at that level.

    • 7 months ago
  35. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    @primeralph if you want, can you show me your series thing you were talking about? You know if you want to.

    • 7 months ago
  36. Confusionist Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    I might just go and ask one of the professors at the college I intern at. Thanks for your help, guys. :)

    • 7 months ago
  37. primeralph Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    First I'd have to convert all to radians.

    • 7 months ago
  38. primeralph Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Then find a way to represent the equation as a DE, or simply use the Taylor power series.

    • 7 months ago
  39. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    what is equivalent to a (1 radian) squared? That bugs me. The little square there.

    • 7 months ago
  40. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    What I'm saying is I'm not used to looking at angles being squared

    • 7 months ago
  41. primeralph Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1388481895287:dw|

    • 7 months ago
  42. primeralph Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    @myininaya Yeah I understand, but you'd have to extend your thinking beyond expecting trig to only apply to angles.

    • 7 months ago
  43. primeralph Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    It will be extensive, but in the end, there might be real solutions.

    • 7 months ago
  44. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    x^2 and 45 will have different units

    • 7 months ago
  45. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    we have x^2=a^2 (degs)^2 and 45 is just in degs not degs^2

    • 7 months ago
  46. primeralph Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    The x^2 term will be set to have some correction factor. After taking a look at it, I think it's solvable algebraically. It's just long.

    • 7 months ago
  47. primeralph Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    And with a lot of restrictions to be imposed.

    • 7 months ago
  48. hartnn Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    those ugly solutions http://www.wolframalpha.com/input/?i=cos%28x%5E2%2B45%29%2Btan%284x%2B90%29+%3D+sin%283x%2B120%29&dataset=

    • 7 months ago
  49. primeralph Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Don't think you used radians. Wolfram is radians by default.

    • 7 months ago
  50. hartnn Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    doesn't make much difference http://www.wolframalpha.com/input/?i=cos%28x%5E2%2Bpi%2F4%29%2Btan%284x%2Bpi%2F2%29+%3D+sin%283x%2B2pi%2F3%29

    • 7 months ago
  51. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    wolfram doesn't want to solve it this is the way input it cos((x deg)^2+45 deg)+tan(4x deg+90 deg)=sin(3x deg+120 deg) http://www.wolframalpha.com/input/?i=cos%28%28x+deg%29%5E2%2B45+deg%29%2Btan%284x+deg%2B90+deg%29%3Dsin%283x+deg%2B120+deg%29

    • 7 months ago
  52. myininaya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    Maybe it doesn't like the unlike units being added either idk

    • 7 months 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.