Question

Найдите наименьшее значение функции y=6x+2П-5cosx-7 на отрезке [П/3,4]

Answer 1

$y=6x+2\pi-5cosx-7 \\y'=6+5cosx \\5cosx=-6 \\cosx=-6/5 - net korney \\f(\pi/3) = 6(\pi/3)+2\pi-5cos(\pi/3)-7 = 3.066 \\f(4) = 6(4)+2\pi-5cos(4)-7 = 26.55$

Answer 2

y=6x+2pi-5cosx-7

y'=6+5cosx

5cosx=-6

cosx=-6/5 - нет решений

f(pi/3) = 6(pi/3)+2pi-5cos(pi/3)-7 = 3.066

f(4) = 6(4)+2pi-5cos(4)-7 = 26.55