Two small arches have the shape of parabolas. The rst is given by f(x) = 1 x2 for 1 if x if 1 and the second by g (x) = 9 (x 9)2 for 2 :1 x :1 6. A board is placed on top of these arches so it rests on both. What is the slope of the Hint: Find the tangent line y = fbc) that intersects y = g (x) at exactly one point. (Give an exact answer. Use symbolic notation and fractions where needed.) 251 slope: W