Объяснение:
y=5x-10cosx ,x∈[-π/2;π]
y'=5+10sinx
y'=0
5+10sinx=0
sinx=-0,5
x=[-π/6+2πn,-5π/6+2πn
1)-π/2≤-π/6+2πn≤π 2)-π/2≤-5π/6+2πn≤π
-1/2≤-1/6+2n≤1 -1/2≤-5/6+2n≤1
-1/3≤2n≤7/6 1/3≤2n≤11/6
-1/6≤n≤7/12 1/6≤n≤11/12
n=0 n∈∅
x=-π/6=-30°
ответ: -30°
