Errors

1. y = 6x^3 + 4x^2 -5x
when you differentiate how can the y remain y
dy/dx = 18x^2 + 8x -5

2. y^2 = x^3 + 16 is in the syllabus differentiating with 2 unknowns
some of you missed this class

differentiate term by term as normal and if the current term is a y term differentiate w.r.t y and then multiply by dy/dx

2y dy/dx = 3x^2

3. 1/y = 4x + 4
no downstairs
y^-1 = 4x + 4
differentiate term by term

-y^-2 dy/dx = 4