Something to do with Trigonometry. (1 Viewer)

P!xel · Mar 3, 2009

$Solve for$ $0\leq x\leq 2\pi$
$\cos x=\frac{1}{2}$

I completely forgot how to do these equations.
It had something to do with ASTC ..

lychnobity · Mar 3, 2009

x = pi/3 or -pi/3

Do the shift cos thing

P!xel · Mar 3, 2009

lychnobity said:
x = pi/3 or -pi/3

Do the shift cos thing

No no, apart from the calculator method,
There was another way to do it.

And I want that method

.

lychnobity · Mar 3, 2009

The general solution?

Well the ASTC one is C means cos is all positive in the 4th quadrant...

P!xel · Mar 3, 2009

lychnobity said:
The general solution?

Well the ASTC one is C means cos is all positive in the 4th quadrant...

Yeah, I found a chart on Wiki.
Tells me about the radians and stuff.

Just to let you know, It's positive in the fist quadrant too

EDIT: Isn't the answer $pi/3$ and $5pi/3$ ?

akatsukisan · Mar 3, 2009

yup. definitely not negative pi/3 - note the domain for x.

P!xel · Mar 3, 2009

akatsukisan said:
yup. definitely not negative pi/3 - note the domain for x.

Thanks a bunch! Credit to you both

Case closed. (Or so I think).