Y=5/(x)+4 y'=-5/x² <0 убывает на R c разрывом в х=0
<span>F(x) = a*cos(2x) + b*sin(4x); </span>
<span><span>F'(x)= -2*a*sin(2x) + 4*b*cos(4x);</span></span>
<span><span><span>F'(7П/12)= 4 = -2*a*sin(7П/6) + 4*b*cos(7П/3) = 2*a*sin(П/6) + 4*b*cos(П/3) = a + 2*b;</span></span></span>
<span><span><span><span>F'(3П/4)= 2 = -2*a*sin(3П/2) + 4*b*cos(3П) = 2*а - 4*b;</span></span></span></span>
<span><span><span><span>a + 2*b = 4;</span></span></span></span>
<span><span><span><span>a - 2*b = 1;</span></span></span></span>
<span><span><span><span>a = 5/2; b = 3/4;</span></span></span></span>
A деталей в час - производительность мастера, b -ученика
a-b=17 a=17+b a=17+b a=17+4 a=21
4a=3*7b 68+4b=21b 17b=68 b=4 b=4
Cosx=-1/2
x=+-2Pi/3+2Pin, n∈Z
<span>b. 15х^2-14ху-10у^2 правильный ответ</span>