作者Honor1984 (奈何上天造化弄人？)
看板Math
标题Re: [中学] 三角函数周期
时间Sat Dec 11 06:59:31 2021
※ 引述《susiseptem (..)》之铭言：
: https://ibb.co/QPdf1wD
: 第三小题 经过1/2周期部分
: 已找到A点 (0,2)
: 500P感谢
a = (1/2)[(7/2) - (-5/2)] = 3
T = 2(4 - 1) = 6
d = (1/2)[(7/2) + (-5/2)] = 1/2
原点左边的第一个交点 = (1-(6/4), 0) = (-1/2, 0)
b = 2π/6 = π/3
c = [(1/2)/6] * 2π = π/6
=> y = 3sin((π/3)x + (π/6)) + 1/2
A的y座标 = 3(1/2) + 1/2 = 2
题目并没说明甲在左端还是右端
假如是甲是在左端，函数随时间右移
A点y座标 = 3sin((π/3)(0 - (6/2)) + (π/6)) + 1/2
= 3sin(-2π/3) + 1/2
= -3/2 + 1/2 = -1
A(0, -1)
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