MEDIUM
JEE Main/Advance
IMPORTANT
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The co-ordinates of a point P referred to a rectangular co-ordinate system where O is the origin are (1,-2). The axes are rotated about O through an angle θ. If the co-ordinates of P in the new system are (k-1, k+1), then k2 is equal to

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Important Questions on Straight Lines

HARD
JEE Main/Advance
IMPORTANT
Centroid of the triangle, the equations of whose sides are 12x2-20xy+7y2=0 and 2x-3y+4=0 is
MEDIUM
JEE Main/Advance
IMPORTANT
The line joining two points A(2,0), B(3,1) is rotated about A in the counter-clockwise sense through an angle 15°. If B goes to C in the new position, then co-ordinates of C is
HARD
JEE Main/Advance
IMPORTANT
The equations of the diagonals of the square formed by the pairs of straight lines 3x2+8xy-3y2=0 and 3x2+8xy-3y2+2x-4y-1=0 are
MEDIUM
JEE Main/Advance
IMPORTANT
Keeping the origin fixed, the coordinate axes are rotated through an angle θ. If the equation of the line xa+yb=1 with respect to new axes is xp+yq=1, then
MEDIUM
JEE Main/Advance
IMPORTANT
The equation of the lines through the origin and which are perpendicular to the pair of straight lines x2-3xy+2y2=0 is
EASY
JEE Main/Advance
IMPORTANT
The value of h for which 3x2-2hxy+4y2=0 represents a pair of coincident lines are
EASY
JEE Main/Advance
IMPORTANT
Find the inclination of the line x-y+3=0 with the positive direction of x-axis.
EASY
JEE Main/Advance
IMPORTANT
Find the angle between the lines joining the points (3,-1) & (2,3) & the points (5,2) and (9,3).