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

CaptainInferior Group Title

Change from rectangular to cylindrical coordinates. Select such set of cylindrical coordinates as θ [0, 2π). (3(3^(1/2)), 3, -5) I've got r = 6 and z = -5. How do I find theta? I keep getting it to be some variation of 30 degrees. :/

  • 2 years ago
  • 2 years ago

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

    First, good job finding r = sqrt(27 + 9) and z = -5. To find theta simply, try drawing a picture of the x-y (or r-theta) plane. This should look like a familiar triangle: a right triangle made by half an equilateral, which confirms your "variation of 30 degrees" (though you'll want to put that into radians). To confirm this conversion, use the following equations: \[x = rsin\theta, y = rcos\theta \implies tan\theta = \frac{rsin\theta}{rcos\theta} \implies \theta = arctan\left(\frac{x}{y}\right) \] Keep in mind that tan(theta) = tan(theta + pi), so check theta against x and y for reasonableness.

    • 2 years 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.