Paramentric curve.

Find the derivative of the first,

u'=2y

Now the derivative of the second,

v'=1+9y^2

Then their ratio is the derivative,

u'/v'=2y/(1+9y^2)

Do not understand.dy/dx where y=f(1-2x) and f ' (x)= sec (x)

Implictly:dy/dx at the point (1,2), where y=y^2-2x^3

y'=2yy'-6x^2

Substitute (1,2)

y'=2(2)y'-6(1)^2

Thus,

y'=4y'-6

Thus,

-3y'=-6

Thus,

y'=2