# Question #ce2e0

##### 1 Answer

Nov 12, 2016

Although we could solve for

#### Explanation:

I assume that you want the second derivative of

Find

Differentiate again:

Simplify a bit,

# = (-y+xdy/dx)/y^2#

Replace

# = (-y+x(-x/y))/y^2#

Simplify again

# = (-y-x^2/y)/y^2#

Clear the fraction in the nmumerator

# = ((-y-x^2/y)*y)/(y^2*y)#

# = (-y^2-x^2)/y^3#

Factor out a #-1)

# = (-(y^2+x^2))/y^3#

Use the original rfelationship

# = (-90)/y^3#