Question

given the curve defined by x^2-siny=y+4
-Find d^2y/dx^2 in terms of x and y only

Answer 1

taking derivative on both sides of equcation
2x-cos(y)y'=y'
2x=y'+cos(y)y'
2x=y'(1+cosy)
2x/(1+cosy)=y'
at y=0
2x/(1+cos0)=y'
2x/(2)=y'
x=y'