Odpowiedź :
[tex]\left(\cos{x}\tan{x}\right)^2-\left(\cfrac{\sin{x}}{\tan{x}}\right)^2=\left(\cos{x}*\cfrac{\sin x}{\cos x}\right)^2-\left(\cfrac{\sin{x}}{\frac{\sin x}{\cos x}}\right)^2=\sin^2x-\cos^2x[/tex]
[tex](cosx\cdot tgx)^{2}-(\frac{sinx}{tgx})^{2} = (cosx\cdot\frac{sinx}{cosx})^{2}-(\frac{sinx}{\frac{sin}{cosx}})^{2} = sin^{2}x-cos^{2}x[/tex]