1. L is a tangent to the circle (x-a)^2 + y^2 =b^2 and Q is a tangent to the circle (x-a)^2 + y^2 =c^2 where b is not equal to B If both L and Q vary so that L is prependicular to Q Find the eqn. of the locua of the intersecting pts. of L and Q
2.Show that the eqn x^2+y^2 -2(R+r)(xcos a +y sina)+ R^2 +2Rr =0 represents a circle of radius r and tangent to the circle x^2+y^2=R^2
10.(a) Let C be the circle x^2 +y^2 =1
Prove that the circumcircle(C') of the triangle formed by the three tangent : x+1=0 y=+/- 開方２ ／４ (x-3) has the eqn. 2x^2 +2y^2 -3x -9=0作者: tong1235 時間: 09-8-8 02:33 PM