If the segment intercepted by the parabola `y^2=4a x` with the line `l x+m y+n=0` subtends a right angle at the vertex, then `4a l+n=0` (b) `4a l+4a m+n=0` `4a m+n=0` (d) `a l+n=0`

If the segment intercepted by the parabola y^(2)=4ax with the line lx+my+n=0 subtends a right angle at the vertex then:

If the line (x)/(l)+(y)/(m)=1 touches the parabola y^(2)=4a(x+b) then m^(2)(l+b)=

The equation of the plane through the intersection of the plane a x+b y+c z+d=0\ a n d\ l x+m y+n+p=0 and parallel to the line y=0,\ z=0. (A) (b l-a m)y+(c l-a n)z+d l-a p=0 (B) (a m-b l)x+(m c-b n)z+m d-b p=0 (c) (n a-c l)d+(b n-c m)y+n d-c p=0 (D) None of these

The direction cosines l, m and n of two lines are connected by the relations l+m+n=0 and lm=0 , then the angle between the lines is

The line lx+my+n=0 touches y^(2)=4x and x^(2)=4y simultaneously then l+2m+3n=

If l, m n denote the lengths of the intercepts made by the circle x ^(2) +y ^(2) - 8x + 10y + 16 =0 on x-axis, y-axis and y = -x respectively, then l + m + n is equal to l + m + n (sqrt2 = 1.41)

If the direction ratio of two lines are given by 3lm-4ln+mn=0 and l+2m+3n=0 , then the angle between the lines, is