# Small question

1. Jan 15, 2006

### Gamma

Solve sin(x-y) when x= [0, pi/2], y=[pi/2, pi].

I am just not familier with the notations.

Does the above mean that I need to find the value of sin (x-y), for (x,y)= (0, pi/2) and (pi/2, pi)?

Why would they write x and y like this??

Thanks.

Gamma

Last edited: Jan 15, 2006
2. Jan 15, 2006

### arildno

I haven't the slightest idea of what they have meant. The notation, if not meaningless, is at the very least obscure and non-standard.

3. Jan 15, 2006

### HallsofIvy

Staff Emeritus
What, exactly, is the wording of the problem? You can solve an equation or, more generally, a "problem" but you can't "solve" a function.
"Solve sin(x-y)" makes no sense. Does the problem ask you, possibly to solve "sin(x-y)= 0" or to find maximum and minimum values for the function?

4. Jan 15, 2006

### Gamma

Thanks guys for the replies.

This is exactly the wording of the problem.

I do felt the same way as you felt. Meaningless question. Only way I would do this is to write sin(x-y)= sinx cosy - cosx siny and substitue values.

Thanks,

Gamma.