{ y = 2sin3 t
Производная от функции, заданной параметрически.
y'x = y't : x't
{ x'(t) = 6·3cos2 t·(–sin t) = –18cos2 t·sin t
{ y'(t) = 2·3sin2 t·cos t = 6sin2 t·cos t
[m]\large y'_{x} = \frac{y'_{t}}{x'_{t}} = \frac{6 \sin^2 t \cos t}{-18 \cos^2 t \sin t}= - \frac{sin t}{3cos t} = - \frac{1}{3} tg\ t[/m]
[m]\large y''_(x) = \frac{(y'_{x})'_{t}}{x'_{t}} = \frac{-1/3 \cdot 1/\cos^2 t}{-18 \cos^2 t \sin t} = \frac{1/\cos^2 t}{54 \cos^2 t \sin t} = \frac{1}{54 \cos^4 t \sin t}[/m]