Question

Вычислите: cos(5x+pi/4)=0
ещё cos(x/5+pi/3)= в корне 2/2

Answer 1

$\cos(5x + \pi \div 4) = 0$
$5x + \frac{\pi}{4} = \frac{\pi}{2} + k\pi$
$5x = \frac{\pi}{2} - \frac{ \pi }{4} + k\pi$
$x = \frac{\pi}{20} + \frac{k\pi}{5}$

Answer 2

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