Найти значение выражения: a) 4arccos(1/2) - 10arcsin(1/2), б) 3arccos(√2/2) - 4arcsin(1/2)

a) $$4\cdot\frac{\pi}{3} - 10\cdot\frac{\pi}{6} = \frac{4\pi}{3} - \frac{5\pi}{3} = -\frac{\pi}{3}$$.
б) $$3\cdot\frac{\pi}{4} - 4\cdot\frac{\pi}{6} = \frac{3\pi}{4} - \frac{2\pi}{3} = \frac{9\pi - 8\pi}{12} = \frac{\pi}{12}$$.