# Math Help - trigonometry

1. ## trigonometry

tg2^@+ctg2^@, if tg@+ctg@=3

2. Originally Posted by bibuciks
tg2^@+ctg2^@, if tg@+ctg@=3
try squarring

(tan @+cot @)^2=(3)^2

and see what you can get from here .

3. ## trigonometry

Thanks, I hope that is it, i don't really have any other options whatsoever
and i have another one I can not quite understand
sin2x+cosx=0
and 2sinx - cos2^x - 2=0

4. Originally Posted by bibuciks
Thanks, I hope that is it, i don't really have any other options whatsoever
and i have another one I can not quite understand
sin2x+cosx=0
and 2sinx - cos2^x - 2=0
$\sin(2x) = 2\sin{x}\cos{x}$ ... substitute, factor, and solve.

$\cos^2{x} = 1 - \sin^2{x}$ ... again, substitute, factor, and solve.