The lines `x cos alpha + y sin alpha = P_1 and x cos beta + y sin beta = P_2` will be perpendicular, if :

The angle between the lines x cos alpha + y sin alpha=p_(1) and x cos beta+y sin beta=p_(2) where alpha gt beta is

The angle between the lines x cos alpha+y sin alpha=p_(1) and x cos beta +y sin beta=p_(2) where alpha gt beta is

If x cos alpha + y sin alpha = x cos beta + y sin beta = 2a then cos alpha cos beta =

The angle between lines x cos alpha+y sin alpha=p_(1), and x cos beta+y sin beta=p_(2), where alpha>beta is

If x cos alpha + y sin alpha = x cos beta + y sin beta = a, 0

The angle between the lines x cos alpha+y sin alpha=p_(1) and x cos beta+y sin beta=p_(2) when alpha>beta

If x cos alpha + y sin alpha = x cos beta + y sin beta "then" "tan" (alpha + beta)/2=

The angle between the lines x cos alpha + y sin alpha = a and x sin beta - y cos alpha = a is

Equations of two straight lines are x cos alpha+y sin alpha=p and x cos beta+y sin beta=p' Show that the area of the quadrilateral formed by the two lines and the perpendiculars drawn from the origin to the lines is (1)/(2sin(B-alpha))[2pp'-(p2+p'2)cos(alpha-beta)}