Відповіді АЛГЕБРА: 21.13

21.13

1) f(x) = 2 sinx + x;

f’(x) = 2 cosx + 1 = 0;

cosx = –12

x = ± (π – π3) + 2πn, n є z;

x = ± 2π3 + 2πn, n є z.

2) g(x) = 3- x2x-2

g’(x) = -2xx-2- (3- x2)(x-2)2 = -2x2+ 4x-3+ x2(x-2)2 = -x2+ 4x-3(x-2)2

–x² + 4x – 3 = 0;

x² – 4x + 3 = 0;

x = 1; x = 3.