MathDB
Today's calculation of Integral 177

Source: Tokyo University of Science entrance exam/Civil Engineering 2007

February 4, 2007
calculusintegrationconicsparabolageometryvideosvector

Problem Statement

On xyxyplane the parabola K: y=1dx2 (d: positive constant number)K: \ y=\frac{1}{d}x^{2}\ (d: \ positive\ constant\ number) intersects with the line y=xy=x at the point PP that is different from the origin. Assumed that the circle CC is touched to KK at PP and yy axis at the point Q.Q. Let S1S_{1} be the area of the region surrounded by the line passing through two points P, QP,\ Q and K,K, or S2S_{2} be the area of the region surrounded by the line which is passing through PP and parallel to xx axis and K.K. Find the value of S1S2.\frac{S_{1}}{S_{2}}.