# How do you use implicit differentiation to find the points on the curve #x^2+y^2=5x+4y# where tangent line is horizontal and where tangent line is vertical?

##### 1 Answer

Horizontal tagts. at

#### Explanation:

**Eqn. of the Curve C** is given to be,

Diff.ing w.r.t. **Chain Rule,** we get,

We know that, **Slope** of a **tangent** to the

**Curve** at the pt.

Now, the slope of **Horizontal Tangent** is

Thus, there are two horizontal tagts. at

Similarly, for the **Vertical Tangent,** we must have **undefined**