whe do u use radians instead of degrees?

Help please!

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Either:

1) When they ask you to
2) Once start a qualification after A-levels

You may also find them useful when attempting to find the arc length of a sector, as such formulae only work in radians.

Reply 2

didgeridoo12uk

you need to use radians for differentiation and integration... so generally then

Reply 3

around

Real men use radians.

Reply 4

SimonM

It allows us to make 'small angle approximations' well, that is chords have similar lengths to arcs for segments with a small angle. This enables us to differentiate the way we expect things to happen.

Reply 5

RightSaidJames

Degrees are an invention to make pre-A-Level Maths more simple to understand. They're not useful for more complicated formulas, such as integration/differentiation, because they're not as accurate and are harder to manipulate mathematically.

Reply 6

Manitude

Calculus and certain geometry problems (both of which have been mentioned previously)

Reply 7

lifeadd1ct

RightSaidJames

They are not as accurate? Degrees are absolutely accurate however the the same cannot be said for radians because when you want to convert to radians from degrees you will have to round the figure up. So if you are unsure please do not post because other people might suffer from your knowledge or should i say, lack of knowledge

Reply 8

username345307

If you mean during exams, at AS use radians when finding the length and area of a sector, and when they tell you to e.g. cos theta = 1/2, what's theta etc.

Reply 9

Dez

Radians make much more sense than degrees, as all they essentially boil down to is fractions of a circle (well, a semicircle). Once you've used them for a while you'll wonder why on earth anyone bothered coming up with degrees. Just don't try and navigate a ship in radians. :wink:

Reply 10

Dez

lifeadd1ct

Radians are usually exact (for example

\sin \frac{\pi}{2} = 0

) when dealing with calculus and advanced trigonometry, whereas degrees will often leave you with irrational numbers.

Reply 11

WhuTom

If you're just talking about in set A-level maths questions regarding trigonometry, (C3 trigonometry for example) then I always switch from degrees to radians as soon as I see the pi symbol. It just means 180 degrees anyway, but if the expression or range is in terms of pi you always do the problem in radians. Don't take this for all types of maths though, I just tried to explain best I could :s-smilie:

For a more detailed, accurate answer (i.e. in maths in general) I'm sure someone else here can explain it through :smile:

Reply 12

py0alb

because then you get the right answer, rather than the wrong answer.

Reply 13

generalebriety

Always use radians, as soon as you know they exist. Degrees are silly, and serve to do nothing other than protect GCSE students from nasty numbers.

lifeadd1ct

Degrees are absolutely accurate however the the same cannot be said for radians because when you want to convert to radians from degrees you will have to round the figure up.

Degrees are absolutely accurate. So are radians. Why would anyone ever want to convert between the two? What a ridiculous idea.

Reply 14

SimonM

Dez

Radians are usually exact (for example

\sin \frac{\pi}{2} = 0

) when dealing with calculus and advanced trigonometry, whereas degrees will often leave you with irrational numbers.

Seriously. Listen to the guy.

\cos 90^{\circ}

isn't approximately 0, it is exactly 0.

Besides which, do you know under what conditions

\cos \frac{p}{q} \pi

is rational?

Reply 15

SirMasterKey

If in an exam paper just look for the super script. An o means degrees, an r means radians.

Most other stuff regarding radians as already been said.

Reply 16

nuodai

Dez

Radians are usually exact (for example

\sin \frac{\pi}{2} = 0

) when dealing with calculus and advanced trigonometry, whereas degrees will often leave you with irrational numbers.

\sin \frac{\pi}{2}

really zero? :p:

But as others have said OP, use radians unless otherwise specified, and leave your answers in terms of

\pi

or surds unless otherwise specified, then you won't go far wrong.

I've not used degrees since starting uni.

Reply 17

tiny hobbit

When differentiating or integrating trig functions.

Or when the question starts talking about pi.

Reply 18

ukdragon37

Always.

Try to use radians as often as possible unless you have to or it's much easier to use degrees (rare). Radians are far more useful and that's the best way to get used to them.