Use "implicit differentiation" to find the slope of tangent when x= sqrt 3 for x^2 + y^2 = 4
i did
dx^2/dx + dy^2/dx = d4/dx
dx^2/dx = 2x
dy^2/dx = 2yy'
d4/dx = 0
2x + 2yy' = 0
y' = - x/y
and then what do i have to do to find the slope of the tangent ?