• November 13th 2009, 01:10 PM
agent2421
Hey can someone help me out with this.

Find the exact radian measure of 400 degrees.

I'm not sure but for the other questions' this is how I solved it... for this one i'm not sure but I'll show what work I do have done.

400/365 x 2 pi

Would that be correct or wrong? If it is wrong how do I solve it if the degrees are more than 365?
• November 13th 2009, 01:30 PM
skeeter
Quote:

Originally Posted by agent2421
Hey can someone help me out with this.

Find the exact radian measure of 400 degrees.

I'm not sure but for the other questions' this is how I solved it... for this one i'm not sure but I'll show what work I do have done.

400/365 x 2 pi

Would that be correct or wrong? If it is wrong how do I solve it if the degrees are more than 365?

$400^\circ \cdot \frac{\pi \, rad}{180^\circ} = \frac{20\pi}{9} \, rad$
• November 13th 2009, 01:44 PM
agent2421
Thanks... how did you get the 2opi/9 though... I understand how you would get 6.981 but how do you make that into an exact radian mesaure?
• November 13th 2009, 01:58 PM
skeeter
Quote:

Originally Posted by agent2421
Thanks... how did you get the 2opi/9 though... I understand how you would get 6.981 but how do you make that into an exact radian mesaure?

$\frac{400\pi}{180}$ reduces to $\frac{20\pi}{9}$
• November 13th 2009, 01:59 PM
agent2421
I know it reduceds to it but how do you show the work behind it.... that's what I don't understand..

I know the answer to 400 pi/180 but why does it become 20pi/9

Sorry if this is a stupid question.... I just don't undertand how you got it from there
• November 13th 2009, 02:02 PM
e^(i*pi)
Quote:

Originally Posted by agent2421
I know it reduceds to it but how do you show the work behind it.... that's what I don't understand..

I know the answer to 400 pi/180 but why does it become 20pi/9

Sorry if this is a stupid question.... I just don't undertand how you got it from there

$\frac{400}{180} = \frac{20}{20} \times \frac{20}{9}$.

As $\frac{20}{20} = 1$ that will cancel
• November 13th 2009, 02:02 PM
skeeter
Quote:

Originally Posted by agent2421
I know it reduceds to it but how do you show the work behind it.... that's what I don't understand..

I know the answer to 400 pi/180 but why does it become 20pi/9

Sorry if this is a stupid question.... I just don't undertand how you got it from there

$\frac{400\pi}{180} = \frac{20 \cdot 20\pi}{20 \cdot 9}$

... cancel the common factor of 20 in the numerator and denominator.