Найдите область значения функции y=-3+4cos2x

Question

Найдите область значения функции y=-3+4cos2x

Answer 1

-1 <= cos 2x <= 1</p>

-4 <= 4cos2x <= 4</p>

-7 <= -3+4cos2x <= 1</span>

y ∈ [-7; 1]

Answer 2

-1<=сos2x<=1</p>

-4<=4cos2x<=4</p>

-7<=-3+4cos2x<=1</p>

[-7;1]