dy/dx其實可唔可以當做分子分母?
(我估應該唔可以,可是phy derive好多時好似當佢做分子分母
再者,pure maths integration一課都好似當佢做分子分母)
例如:
由dN/dt = - kN
derive成N=Noe^-kt
dy/dx其實可唔可以當做分子分母?
2011-04-20 11:59 pm
回答 (3)
2011-04-25 11:03 am
y² - y + 1 = x⁵ + 6x⁴ - 9x³ - 2x² - 5x + 3
dy/dx = ？
2ydy - dy = 5x⁴dx + 24x³dx - 27x²dx - 4xdx - 5dx
(2y - 1)dy = (5x⁴ + 24x³ - 27x² - 4x - 5)dx
dy/dx = (5x⁴ + 24x³ - 27x² - 4x - 5)/(2y - 1)
另外：
y = f(t)
x = g(t)
dy/dx = (dy/dt)/(dx/dt)
不管它原義是什麼，運用起來就「像」分子分母
dy/dx = ？
2ydy - dy = 5x⁴dx + 24x³dx - 27x²dx - 4xdx - 5dx
(2y - 1)dy = (5x⁴ + 24x³ - 27x² - 4x - 5)dx
dy/dx = (5x⁴ + 24x³ - 27x² - 4x - 5)/(2y - 1)
另外：
y = f(t)
x = g(t)
dy/dx = (dy/dt)/(dx/dt)
不管它原義是什麼，運用起來就「像」分子分母
2011-04-21 6:15 am
No. d/dx is actually a sign for derivative.
But in differential, dx can be regarded as denominator
2011-04-20 22:16:43 補充：
Just like integration we are using "DIFFERENTIAL", not "DERIVATIVE"
But in differential, dx can be regarded as denominator
2011-04-20 22:16:43 補充：
Just like integration we are using "DIFFERENTIAL", not "DERIVATIVE"
2011-04-21 5:52 am
可以
圖片參考：http://upload.wikimedia.org/math/7/3/f/73f36cb9cdd93809225199524f9d4233.png
Differentiation is a method to compute the rate at which a dependent output y changes with respect to the change in the independent input x.
圖片參考：http://upload.wikimedia.org/math/b/5/2/b520946f113297324c17008d01cb8bd2.png
圖片參考：http://upload.wikimedia.org/math/7/3/f/73f36cb9cdd93809225199524f9d4233.png
Differentiation is a method to compute the rate at which a dependent output y changes with respect to the change in the independent input x.
圖片參考：http://upload.wikimedia.org/math/b/5/2/b520946f113297324c17008d01cb8bd2.png
參考: wikipedia
收錄日期: 2021-04-25 17:03:52
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