0 \\a>7 \sin x - 5 \cos x = g(x) \\ g'(x) = 7 \cos x +5 \sin x = 0 \Rightarrow x = \arctan(-\frac{5}{7}) \\ a > 7 \sin (\arctan(-5/7))-5 \cos(\arctan(-5/7)) \approx 8.61" alt="f(x) = ax+7\cos x+5\sin x \\ f'(x) = a - 7\sin x + 5 \cos x >0 \\a>7 \sin x - 5 \cos x = g(x) \\ g'(x) = 7 \cos x +5 \sin x = 0 \Rightarrow x = \arctan(-\frac{5}{7}) \\ a > 7 \sin (\arctan(-5/7))-5 \cos(\arctan(-5/7)) \approx 8.61" align="absmiddle" class="latex-formula">
Ответ: а=9