※ 引述《loveRyoko ( )》之銘言：
: 1. e^x dx + (e^x coty + 2y cscy)dy = 0
e^xdx + ( e^x*(cosy/siny) + 2y*(1/siny) )dy = 0
*siny e^x siny dx + e^x cosy dy +2y dy = 0
sinyde^x + e^xdsiny + 2y dy =0
de^xsiny +d y^2 = 0
e^xsiny + y^2 = c
: 2. (-xy sinx + 2y cosx)dx + (2x cosx)dy = 0
-xysinx dx + 2cosx (xdy+ydx) = 0
-xy sinx dx + 2 cosx d xy =0
- sinx/cosx dx + 2 / xy dxy = 0
ln cosx + 2 ln xy =c
(xy)^2 * cosx = c
xy = (c/cosx)^(1/2)
y = 1/x * (c/cosx)^(1/2)
: 5.http://tinyurl.com/yh57o2j
: 問(c)小題而已
: 6.http://tinyurl.com/yze27an
: 不懂RC電路圖套在工數裡面要怎麼解
: 7. e^(sin3t) 和 sin(sint)這兩個函數 是周期函數嗎? 不知道怎麼判斷
: 謝謝大家~
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