Straight lines - Past JEE

1. The set of lines ax+by+c = 0 where a,b,c satisfy the relation 3a+2b+4c = 0 is concurrent at the point --------------. (JEE, 1982)


2. The straight lines x+y = 0, 3x+y-4 = 0, x+3y-4 = 0 for a triangle which is

a. isoscles
b. equilateral
c. right angled
d. none of these

(JEE 1983, Scr)


3. Three lines px+qy+r = 0, qx+ry+p =0, and rx+py+q +0 are concurrent if:

a. p+q+r + 0
b. p²+q²+r² = pq+rq+rp
c. p³+q³+r³ = 3pqr
d. none of these



4. The points (0,8/3), (1,3) and (82,30) are vertices of:

a. an obtuse angled triangle
b. an acute angled triangle
c. a right angled triangle
d. an isosceles triangle
e. none of these

(JEE 1986)

5. State whether the following statement is true or false
The lines 2x +3y +19 = 0 and 9x+6y-17 = 0 cut the coordinate axes in concyclic points.
(JEE 1988)