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

For a gt b gt c gt 0 , if the distance between (1,1) and the point of intersection of the line ax+by-c=0 and bx+ay+c=0 is less than 2sqrt2 then, (A) a+b-cgt0 (B) a-b+clt0 (C) a-b+cgt0 (D) a+b-clt0

Direction ratios of two lines are a ,b ,ca n d1//b c ,1//c a ,1//a bdot Then the lines are ______.

Direction ratios of two lines are a ,b ,c a n d1//b c ,1//c a ,1//a bdot Then the lines are ______.

If the vectors ahati+bhatj+chatk,bhati+chatj+ahatk and chati+ahatj+bhatk are coplanar and a,b,c are distinct then (A) a^3+b^3+c^3=1 (B) a+b+c=1 (C) 1/a+1/b+1/c=1 (D) a+b+c=0

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