R(–1, 4),S(11,–8)divide AB harmonically in the ratio 3 : 2 then A, B are

R(−1,4),S(11,−8)R,S divides AB¯harmonically in the ratio 3 : 2⇒ AB divides RS¯in the ratio  m−n : m+n=3−2  :  3+2=1  :  5A=S−5R1−5=(11,−8)−(−5,20)−4=(−4,7)B=S+5R1+5=(11,−8)+(−5,20)6=(1,2)