Graphing Prevents Overthinking
Geometry
Level
1
There are four lines that are tangent to both circles
\[ { x }^{ 2 }+{ y }^{ 2 }=1 \quad \text{ and } \quad ({ x }-6)^{ 2 }+{ y }^{ 2 }=4. \]
What is the sum of the slopes of these four lines?
by
Yash Choudhary