liczba-cos12circ-cdot-sin78circsin12circ-cdot-cos78circ-jest-rowna

$\displaystyle \frac{1}{2}$\displaystyle \frac{1}{2}

$\displaystyle \frac{\sqrt{2}}{2}$\displaystyle \frac{\sqrt{2}}{2}

$\displaystyle \frac{\sqrt{3}}{2}$\displaystyle \frac{\sqrt{3}}{2}

$1$1