ellipse--parametric equation

👨🏻‍🏫 學術台數學

jackie

2010-10-28 6:20 am

ellipse--parametric equation
點解要選x=acos(alpha)
y=bsin(alpha)
在座標上有什麼意思?
為何不用x=asin(alpha)
y=bcos(alpha)

回答 (1)

wkho28

2010-10-28 9:27 am

✔ 最佳答案

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2010-10-28 01:30:23 補充：
The last sentence should be :

However, it is a common practice that the rotating axis moves anti-clockwise from the positive x-axis direction.

Thts is why we have
x=a cos α
y=b sin α

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