# Sine function

• Jan 18th 2009, 01:01 PM
live_laugh_luv27
Sine function
Find the range of the function f(t) = 2sinθ.

How would I do this problem?
• Jan 18th 2009, 01:26 PM
Mush
Quote:

Originally Posted by live_laugh_luv27
Find the range of the function f(t) = 2sinθ.

How would I do this problem?

$f(t)$ means a function of t, but on the right hand side you have a function of $\theta$.
• Jan 18th 2009, 02:09 PM
live_laugh_luv27
Quote:

Originally Posted by Mush
$f(t)$ means a function of t, but on the right hand side you have a function of $\theta$.

That's what the problem states...
• Jan 18th 2009, 02:42 PM
Mush
Quote:

Originally Posted by live_laugh_luv27
That's what the problem states...

That doesn't make sense to me.

Are you sure it's not:

$f(t) = 2\sin(t)$

or

$f(\theta) = 2\sin(\theta)$

??

In any case, the range of a function, is the range of values of $f(t)$ or $f(\theta)$ that emerge as $t$ or $\theta$ vary across their domain.

Your function is a sine wave, hence $t$ or $\theta$ vary from $-\infty$ and $\infty$. $f(t)$ or $f(\theta)$, a sine wave ranges between positive and negative its amplitude. Do you know what the amplitude of your sinewave is? Let the amplitude be $a$.

Hence the range is

$-a \leq f(t) \leq a$

or

$-a \leq f(\theta) \leq a$

But what is a? That's the bit you have to do!

Depending on which was meant. Unless your equation is actually correct and there's an extra element to this question that I don't understand.