General Discussions

So I was bored one day in math class (Calc ab) and as many people do I pulled out my trusted TI-83 and was graphing random things. And I came across an enigma.

I graphed "log(X)/sin(x^cos(X))" (in radians) with the window set to
"Xmin=0
Xmax=10"

I then set the window to normal (Xmin=-10) and I got an error. And I thought why? Because the log of a negative doesn't exist, so I graphed "log(abs(X))/sin(X^cos(X))" with the window set to normal. It gave me the same error

So after a little bit of work, I discover that when X=-1 (for example) sin(-1^cos(-1)) = -.115+.904i so that made sense. But shouldn't the same thing happen after X=2pi?

Any explanation would help greatly.

Maybe it was because you can actually divide by 0 with that equation, and we all know it means the end of the universe if you try.

Set the domain for 0 >= x >= 2*pi

Division by zero shouldn't matter when graphing an equation as the calculator will either insert a hole or an asymptote where the equation would be undefined. It doesn't know now to deal with non-real values though.

[Edited by Neo7, 10/13/2010 7:19:56 AM]

jimmy buffet said it best in the song of the same name "Math Sucks."

But that's the thing, it lets you graph the equation even when the domain is set to 0>=x>=10, rather than 0>=x>=2*pi. The only time it doesn't let you is when the domain is -10>=x>=10.

Ugh. I understand what you're talking about. This isn't good. College is learning me things.