Question

arătati ca sin2x supra 1+cos2x=tgx

Answer 1

$\frac{sin2x}{1+cos2x} = tg x$

sin2x = 2sinxcosx
cos2x = $-1 + 2cos^2x$

$\frac{2cosxsinx}{1-1+2cos^2x}$
$\frac{2cosxsinx}{2cos^2x}$
$\frac{cosxsinx}{cos^2x}$
$\frac{sinx}{cosx} = tg x$