найти множество значений функции y=4+3 cos2x

y = 1-cosx

cosx: [-1; 1], E(y): [0; 2


y = 1 - 4cos2x

cos2x: [-1; 1], E(y): [-3; 5]



y = (1/2) sinx*cosx - 1 = (sin2x)/4 -1

sin2x: [-1; 1], E(y): [(-5/4); (-3/4)]  
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