IF l,m,n are rational the roots of ` (m +n) x^2 -(l+m+n)x+l =0` are

If L+M+N=0 and L,M,N are rationals the roots of the equation (M+N-L)x^(2)+(N+L-M)x+(L+M-N)=0 are

Find the acute angle between the lines (x-1)/(l)=(y+1)/(m)=(1)/(n) and =(x+1)/(m)=(y-3)/(n)=(z-1)/(l) where l>m>n, and l,m,n are the roots of the cubic equation x^(3)+x^(2)-4x=4

If l , m, n are the direction cosines of a line, then: a) l^(2)+m^(2)+n^(2)=1 b) l^(2)+m^(2)+n^(2)=0 c) l+m+n=1 d) l+m+n=0

The area of the quadrilateral formed by two pairs of lines l^(2) x^(2)-m^(2) y^(2)-n(l x+m y)=0 and l^(2) x^(2)-m^(2) y^(2)-n(L x-m y)=0 is

If one root of the equation lx^(2)+mx+n=0 is (9)/(2) equal to (l,m and n are positive integers) and (m)/(4n)=(l)/(m), then l+n is equal to

If l,m and n are three straight lines such that l||m and l||n then prove that m||n .

Evaluate : ( x^(m + n ) times x^(n + l ) times x^( l + m ) ) / ( x^m times x^n times x^l )