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# Converting to a+jb form Watch

1. 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.
2. (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
3. (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.
4. (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.

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Updated: September 19, 2016
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