Khan Academy: Algebra: Conic Sections: Iit Jee Circle Hyperbola Common Tangent 3

The third video of five on solving an IIT JEE problem concerning a tangent line that is common both to a circle and a hyperbola. This video uses algebra to determine where the arbitrary line y = mx + b could intersect the given hyperbola at only one point (the point of tangency). This allows for constraints to be made on both the slope and y-intercept of the tangent line. From here there are two equations in two variables (m and b) that can be solved for m. [8:55]