maths Question
2013-07-07 12:04 am
回答 (2)
2013-07-10 10:22 pm
✔ 最佳答案
The answer is D. 13-1 <= sin(3x) <= 1
-2 <= 2sin(3x) <= 2
-3 <= 2sin(3x)-1 <= 1
When 2sin(3x)-1 is negative, the minimum is -3，it turns 9 after squaring.
When 2sin(3x)-1 is positive, the maximum is 1，it turns 1 after squaring.
Therefore, the greatest value of (2sin(3x)-1)^2+4 is (-3)^2+4 = 9+4 = 13
2013-07-07 12:35 am
sin 最大係1，(2sin3x-1) 最大係1，所以1^2+4 最大係5。
答案係 B. 5
答案係 B. 5
收錄日期: 2021-04-23 23:44:57
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