Найдите значение выражения A=arccsin (sin 5pi/4)

Решите задачу:

$A=arcsin(sin \frac{5\pi }{4})=arcsin(sin(\pi +\frac{\pi}{4}))=arcsin(-sin\frac{\pi}{4})=\\\\=-\underbrace {arcsin(sin\frac{\pi}{4}}_{\frac{\pi}{4}})=-\frac{\pi}{4}\\\\\\P.S.\; \; arcsin(sin \alpha )= \alpha \; ,\; \; esli\; \; \; \; -\frac{\pi }{2}\leq \alpha \leq\frac{\pi }{2} \; .\\\\ \frac{5\pi }{4}\notin [\, -\frac{\pi }{2} ,\frac{\pi }{2} \, ] \; \; ,\; \; \frac{\pi }{4}\in [\, -\frac{\pi }{2}, \frac{\pi }{2}\, ]$