Find dy/dx and d2y/dx2 . x = 2 sin t, y = 3 cos t, 0 < t < 2π
Solution:
Given: x = 2 sin t and y = 3 cos t
We know that differentiation of parametric functions is
dy/dx = dy/dt/ dx/dt
x = 2 sin t
dx/dt = 2 cos t
y = 3 cos t
dy/dt = - 3 sin t
Substituting the values
dy/dx = -3 sin t/ 2 cos t
= -3/2 tan t
Again by differentiation
d2y/dx2 =[d/t(dy/dx)]. dt/dx
So we get
d2y/dx2 = -3/2 sec 2t/ 2 cost
= -3/4 sec3t
Therefore, dy/dx = -3/2 tan t and d2y/dx2 = -3/4 sec3t
Find dy/dx and d2y/dx2 . x = 2 sin t, y = 3 cos t, 0 < t < 2π
Summary:
If x = 2 sin t, y = 3 cos t, 0 < t < 2π dy/dx = -3/2 tan t and d2y/dx2 = -3/4 sec3t.
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