PDA

View Full Version : Trig question



Robert602
05-12-2004, 12:23 PM
A fairly simple equation by the looks of it but one I dont have a clue how to solve, somebody give me a hand please:

46/27 = tan(1.5x)/tan(x)

I've managed to get the solution graphically, but how would it be done algebraically, is there an important trig identity I shoud know?

Thanks a lot.

DavidP
05-12-2004, 01:13 PM
i assume you are solving for x? or what?

Robert602
05-12-2004, 01:17 PM
Yeah, I'm trying to solve for x (in radians).

1veedo
05-12-2004, 02:18 PM
man, I hate radians! hense I don't like the trig functions that came standard with my compiler.

Thantos
05-12-2004, 04:58 PM
tan(1.5x) =
tan(x + .5x) =
(tan (x) + tan(.5x))/(1-tan(x)tan(.5x))
or
(sin(x)cos(.5x)+cos(x)sin(.5x)) / (cos(x)cos(.5x)-sin(x)sin(.5x))

so divide that by tan(x) and reduce reduce reduce :)