若三點A(2,2)B(a,0)C(0,b)(ab不等於0)共線,求證1/a+1/b=1/2

若三點A(2,2)B(a,0)C(0,b)(ab不等於0)共線,求證1/a+1/b=1/2

三點共線,那麼
(2-0)/(2-a)=(2-b)/(2-0)化簡得
ab-2b-2a=0都除2ab
1/2=1/a+1/b