# Math Help - Trig equation

1. ## Trig equation

I seem to get a maths error on my calculator when i put $cos^{-1} (-2)$

$5cos(x)x+10=0$

$(0=

Thanks

EDIT: Please move to trig thread. I accidentally posted in the wrong one.

2. Originally Posted by deltaxray

I seem to get a maths error on my calculator when i put $cos^{-1} (-2)$

$5cos(x)x+10=0$

$(0=

Thanks

EDIT: Please move to trig thread. I accidentally posted in the wrong one.
HI

U mean $5\cos x+10=0$ ?? If so ,

$\cos x=-2$

Its math error because the minimum of cos is -1 . Sketch the cos graph , it should be clear to you .