If the function y = cos (ω x + π / 2) is monotonically increasing on (0, π / 4), then the value range of ω? If the function y = cos (ω x + π / 2) increases monotonically on (0, π / 4), then the value range of ω? A (-∞,2) B [2,0) C (0,2] D[2,+∞)

If the function y = cos (ω x + π / 2) is monotonically increasing on (0, π / 4), then the value range of ω? If the function y = cos (ω x + π / 2) increases monotonically on (0, π / 4), then the value range of ω? A (-∞,2) B [2,0) C (0,2] D[2,+∞)

Maybe the title is wrong, B option should be [- 2,0), so the answer should be B
Because the smaller the Omega, the larger the period of the function
If ω is negative, the function will increase monotonically on (0, π / 4)