Question

cos495 + tg 1800 вычислите

Answer 1

Ответ:

$cos495^\circ +tg1800^\circ =cos(360^\circ +135^\circ )+tg(360^\circ \cdot 5+0^\circ )=\\\\=cos(180^\circ -45^\circ )+tg0^\circ =-cos45^\circ +0=-\dfrac{\sqrt2}{2}$