Răspuns :
AB=√[(xA+xB)²+(yA+yB)²]=
=√[(2+5)²+(-1+m²]=
=√25+1-2m+m²
√25+1-2m+m²=1 Ridicam la patrat
m²-2m+25=0
delta=4m²-100
Egalam delta cu 0:
4m²-100=0 Impartim prin 4
m²-25=0
m∈{-5,5}
=√[(2+5)²+(-1+m²]=
=√25+1-2m+m²
√25+1-2m+m²=1 Ridicam la patrat
m²-2m+25=0
delta=4m²-100
Egalam delta cu 0:
4m²-100=0 Impartim prin 4
m²-25=0
m∈{-5,5}