Graphing a Hyperbolic Trigonometric Function: Radian vs. Degree Mode

[sophzilla]

Hello - I'm sorry if this question doesn't really apply here, but the Math & Science Tutorial wasn't very active so I decided to come here instead...

What should my calculator mode be in when graphing a hyperbolic WITH trigonometric function? (My function is sinx*coshx - sinhx*cosx). I'm getting 2 different graphs between radian and the degree mode.

I think it should be in the radian mode...?

Thanks for your help.

 

[FrogPad]

What kind of calculator are you using?

I'll assume for a minute that you are using a TI-83/84. When you press the "WINDOW" key (next to "Y=") what is your X min, X max, Y min, Y max values?

The default is:
Xmin = -10
Xmax = 10
Ymin = -10
Ymax = 10

Lets say you are plotting cos(x)
Well from basic trig you know that:
cos(x=\frac{\pi}{2}) = 0
and that \frac{\pi}{2}=90
where 90 is in degrees.

So if you have your default Xmin, Xmax, ... values above, then this means that you are allowing the calculator to start at the value of -10 and increment up to 10.

If your calculator is in degree mode you will never see cox(x) hit 0. Do you see why this is? Our range is too small. But if you put your calculator in radian mode, then guess what... \frac{\pi}{2}=1.571 so we are within our range of values between -10 and 10, thus we will see something useful.

Also, if we let y=cos(x). Then, y will range from -1 to 1. So you only need to set
Ymin = -1
and
Ymax = 1

 

[FredGarvin]

Pretty much any math class I have ever taken past high school used radians. I would suggest the same. It really doesn't matter which one you use as long as both functions get the same type of argument, either degrees or radians. Don't mix them.