Posted by T.Gracken on October 22, 2002 at 10:13:56:
In Reply to: Re: area posted by T.Gracken on October 22, 2002 at 07:44:49:
: : : what have you tried already?
: : : I am not going to attempt an answer for this without more info on what you have attempted and why. This is too extensive a problem to explain without more info!
: : I'm stuck after getting this far:
: : Sin(x+y)Cos(y) >= Sin(x)
: : Sin(x)Cos(y)Cos(y) + Cos(x)Sin(y)Cos(y) - Sin(x) >= 0
: : Sin(x)(Cos(y)Cos(y) - 1) + Cos(x)Sin(y)Cos(y) >= 0
: you still haven't answered any of my questions... so if you just want to manipulate the expression, how about this:
: Sin(x)(Cos(y)Cos(y) - 1) + Cos(x)Sin(y)Cos(y) >= 0 {your last step}
: => Sin(x)(Cos2(y) - 1) + Cos(x)Sin(y)Cos(y) >= 0
: => Sin(x)(1 - Sin2(y) - 1) + Cos(x)Sin(y)Cos(y) >= 0
: => -Sin(x)Sin2(y) + Cos(x)Sin(y)Cos(y) >= 0
: => Sin(y)[Cos(x)Cos(y) - Sin(x)Sin(y)] >= 0
: => Sin(y)Cos(x+y) >= 0
: Although I don't know where that will lead you (yet).
: By the way; This is a very complex problem. Are you sure you copied it correctly (and entirely)? Including the directions? Have you studied surfaces and/or parametric equations? The more I look at the problem you wrote, the more I tend to believe there is something you haven't told us.