Given a + b + c + d = 0, which of the following statements are correct:
'a, b, c, and d must each be a null vector,

Which of the followings are relations from {x, y, z} to {a, b, c, d} {a, b, c, d, x, y, z}

Which of the followings are relations from {x, y, z} to {a, b, c, d} {(a, x),(b,y), (c, z)}

Which of the followings are relations from {x, y, z} to {a, b, c, d} {(x, c), (y, y)}

If a , b , c , are rational and a + b + c= 0 . Show that the roots of the following equation are rational. (b + c)x^2 + (c + a)x + (a + b) = 0

If a , b , c , are rational and a + b + c= 0 . Show that the roots of the following equation are rational. (b + c -a)x^2 +(c + a - b)x + (a + b- c) = 0

Which of the followings are relations from {x, y, z} to {a, b, c, d} ,{(x, d),(y, b),(z, c)}

Which of the following pairs of sets are disjoint?C={a,e,i,o,u},D={c,d,e,f}.

If a, b, c, d are in G.P., show that each of the following three term are also in G.P. a+b,b+c,c+d .

If a , b , c , are rational and a + b + c= 0 . Show that the roots of the following equation are rational. ax^2 + bx + c = 0 .

If a,b,c,d are in G.P show that each of the following three term are also in G.P a+b,b+c,c+d .