c4

Given that siny = xy + x^2 , find dy/dx in terms of x and y.
Working out :
cos y dy/dx = (x+y) dy/dx + 2x
cos y dy/dx - (x+y)dy/dx = 2x
dy/dx ( cos y - x - y) = 2x
dy/dx = 2x / ( cos y -x - y)
this is incorrect according to mark scheme??

Reply 1

the bear

20

Original post by Chelsea12345

Given that siny = xy + x^2 , find dy/dx in terms of x and y.
Working out :
cos y dy/dx = (x+y) dy/dx + 2x
cos y dy/dx - (x+y)dy/dx = 2x
dy/dx ( cos y - x - y) = 2x
dy/dx = 2x / ( cos y -x - y)
this is incorrect according to mark scheme??

it should say xdy/dx + y + 2x