text: ### Home > CALC > Chapter 6 > Lesson 6.4.2 > Problem6-148
  
  6-148.
  
  The last remaining parent graph without a derivative is the circle $x^2 + y^2 = 1$. Find $\frac { d y } { d x }$ for this graph.
  
  Recall that a circle is NOT a function.
  Before differentiating, you could solve for $y$ and get
  Then find the derivative of each piece separately, or.....
  You could use implicit differentiation!
  
  $\frac{d}{dx}(x^{2}+y^{2})=\frac{d}{dx}(1)$