# Difference between theta and x?

• Aug 5th 2011, 06:49 AM
explodingtoenails
Difference between theta and x?
I'm so confused with trig...

Why is the graph of sin(theta) different from the graph of sin(x)?
• Aug 5th 2011, 06:59 AM
Plato
Re: Difference between theta and x?
Quote:

Originally Posted by explodingtoenails
I'm so confused with trig...
Why is the graph of sin(theta) different from the graph of sin(x)?

There is no difference.
If each of $\displaystyle \theta,~t,~&~x$ is a real variable
then the graphs $\displaystyle \sin(\theta),~\sin(t),~&~\sin(x)$ are identical.
• Aug 5th 2011, 07:02 AM
Opalg
Re: Difference between theta and x?
Quote:

Originally Posted by explodingtoenails
I'm so confused with trig...

Why is the graph of sin(theta) different from the graph of sin(x)?

It isn't different, provided that $\displaystyle \theta$ and $\displaystyle x$ are measured in the same units. But if $\displaystyle \theta$ is measured in radians and $\displaystyle x$ is measured in degrees (say), then the scale of the horzontal axis will be different.
• Aug 5th 2011, 09:03 AM
TheChaz
Re: Difference between theta and x?
Quote:

Originally Posted by explodingtoenails
I'm so confused with trig...

Why is the graph of sin(theta) different from the graph of sin(x)?

In light of the correct responses given, it makes sense to ask:
What makes YOU think that they are different?
• Aug 5th 2011, 10:33 AM
HallsofIvy
Re: Difference between theta and x?
Another point "x" and "y" are typically used in a rectangular coordinate system and "r" and "$\displaystyle \theta$" are used in polar coordinates. You can, of course, use whatever letters you wish.

The graph of "y= sin(x)", in rectangular coordinates is the "sine wave".
The graph of "$\displaystyle r= sin(\theta)$", in polar coordinates is the circle with center at (0, 1/2) and radius 1/2, as $\displaystyle \theta$ goes from 0 to $\displaystyle \pi$.

But, again, the difference is because of the coordinate systems, not what the variables are called.
• Aug 5th 2011, 12:39 PM
explodingtoenails
Re: Difference between theta and x?
Ahh I see. Thanks guys!!!