>>907
(1)
y = arcsin(x)
x = sin(x)
x/√(1-x^2) = sin(x)/cos(x) = tan(x)

(2)
x = 3cos(t)
y = 2sin(t)

(x/3)^2 + (y/2)^2 = 1

xで微分すると
(2/9)x + (1/2) y (dy/dx) = 0
もう1回微分すると
(2/9) + (1/2) (dy/dx)^2 + (1/2)y (d^2 y/dx^2) = 0