A geometric solution to the first problem: Draw a line from (4,2) to (0,0). The length of this line is . Now, the two tangent lines will intersect the unit circle at a point 1 unit from the origin, and because the tangent lines will be perpendicular to the radius drawn to the points, the distance from (4,2) to either of these points will be . To find the points, then, we can use the intersection of the two circles and .