Найти область определения и указать множество значений функции f(x)=0,5arccos(4-5x)-2

Y = arccos (x)
D(y) = [ - 1; 1]
E(y) = [ 0; pi]

y = arccos (5x)
D(y) = [ - 1/5; 1/5]
E(y) = [ 0; pi]

y = arccos ( - 5x)
D(y) = [ - 1/5; 1/5]
E(y) = [ 0; pi]

y = arccos (4 - 5x)
D(y) = [ 3/5; 1]
E(y) = [ 0; pi]

y = 0,5*arccos (4 - 5x)
D(y) = [ 3/5; 1]
E(y) = [ 0; pi/2]

y = 0,5*arccos (4 - 5x) - 2
D(y) = [ 3/5; 1]
E(y) = [ - 2; pi/2 - 2]