If the direction cosines of a line are `1/c,1/c,1/c` rthen (A) `c.0` (B) `0ltclt1` (C) `c=+-sqrt(3)` (D) `cgt2`

If the direction cosines of a line are ((1)/(c ) , (1)/(c ), (1)/(c )) then :

If the direction cosines of a straighat line are k,k,k the (A) kgt0 (B) 0ltklt1 (C) k=1 (D) k=1/sqrt(3) or -1/sqrt(3)

The direction cosines of x-axis are (A) 0,0,1 (B) 1,0,0 (C) 0,1,0 (D) 0,1,1

The direction cosines of line joining (1,-1,1) and (-1,1,1) are (A) 2,-2,0 (B) 1,-1,0 (C) 1/sqrt(2)-1/sqrt(2),0 (D) none of these

The direction cosines of any normal to the xy-plane are (A) 1,0,0 (B) 0,1,0 (C) 1,1,0 (D) 0,01

A straight line L on the xy-plane bisects the angle between OX and OY. What are the direction cosines of L? a.(:(1/sqrt(2)),(1/sqrt(2)),0:)b(:(1/2),(sqrt(3)/2),0:)c.(:0,0,1:)d(:(2/3),(2/3),(1/3):)

Let a,b,c in R such that a^(2)+b^(2)+c^(2)=2bc,a^(2)+b^(2)+c^(2)!=0 . Then which of the following points lie on the line ax+by+c=0 , is : (A) (-1,2) (B) (1,2) (C) (-1,-2) (D) (2,-1)

If a,b,c real in G.P.then the roots of the equation ax^(2)+bx+c=0 are in the ratio (1)/(2)(-1+sqrt(3)) b.(1)/(2)(1-i sqrt(3)) c.(1)/(2)(-1-i sqrt(3)) d.(1)/(2)(1+i sqrt(3))

If agt0, bgt0, cgt0 and the minimum value of a^2(b+c)+b^2(c+a)+c^2(a+b) is kabc, then k is (A) 1 (B) 3 (C) 6 (D) 4

If a b+b c+c a=0 , then what is the value of (1/(a^2-b c)+1/(b^2-c a)+1/(c^2-a b)) ? (a) 0 (b) 1 (c) 3 (d) a+b+c