Just one sec...
Hey! Sign in to get help with your study questionsNew here? Join for free to post

Converting to a+jb form

Announcements Posted on
Take our short survey, £100 of Amazon vouchers to be won! 23-09-2016
    • Thread Starter
    Offline

    1
    ReputationRep:
    I'm having problems with this, the annoying thing is I've done it, however I can't remember how I did the previous example or I have changed the mode on my calculator and it's destroyed what I was doing.

    I have to convert this;

    2.4 /_ -(π/6)

    So I have;

    a= r cos ϴ = 2.4 cos -30 = ???

    b= r sin ϴ = 2.4 sin -30 = ???

    I input it into my casio and just comes up with maths error, I changed my calculator to radians and then back and now I don't know why I can't do this.

    So if someone could walk me through it would be great, cheers.
    Offline

    3
    ReputationRep:
    (Original post by Brainfrozen)
    I'm having problems with this, the annoying thing is I've done it, however I can't remember how I did the previous example or I have changed the mode on my calculator and it's destroyed what I was doing.

    I have to convert this;

    2.4 /_ -(π/6)
    I don't know that that is...

    So I have;

    a= r cos ϴ = 2.4 cos -30 = ???

    b= r sin ϴ = 2.4 sin -30 = ???

    I input it into my casio and just comes up with maths error, I changed my calculator to radians and then back and now I don't know why I can't do this.

    So if someone could walk me through it would be great, cheers.
    You should really know off the top of your head that cos(-30) = sqrt(3)/2 and sin(-30) = -1/2.

    Anywho, if you're sure you're in degree mode then trying doing 2.4 sin (-30), i.e: explicitly use the bracket
    • Thread Starter
    Offline

    1
    ReputationRep:
    (Original post by Zacken)
    I don't know that that is...



    You should really know off the top of your head that cos(-30) = sqrt(3)/2 and sin(-30) = -1/2.

    Anywho, if you're sure you're in degree mode then trying doing 2.4 sin (-30), i.e: explicitly use the bracket
    I have no idea what's gone wrong, tried it on my work's calculator and it works fine. I've clearly changed something in the calculator and it's not working.
    Offline

    3
    ReputationRep:
    (Original post by Brainfrozen)
    I have no idea what's gone wrong, tried it on my work's calculator and it works fine. I've clearly changed something in the calculator and it's not working.
    If you've got a casio, try pressing mode and then clearing your settings.
 
 
 
Write a reply…

Reply

Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. Oops, you need to agree to our Ts&Cs to register
  2. Slide to join now Processing…

Updated: September 19, 2016
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

Poll
Who is going to win Bake Off?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read here first

Equations

How to use LaTex

Writing equations the easy way

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups
Study resources

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.