MEDIUM
JEE Main
IMPORTANT
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Let the foot of perpendicular from a point P(1,2,-1) to the straight line L:x1=y0=z-1 be N. Let a line be drawn from P parallel to the plane x+y+2z=0 which meets L at point Q. If α is the acute angle between the lines PN and PQ, then cosα is equal to              .

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Important Questions on Three Dimensional Geometry

EASY
JEE Main
IMPORTANT
If the lines x-k1=y-22=z-33 and x+13=y+22=z+31 are co-planar, then the value of k is _______.
EASY
JEE Main
IMPORTANT
Let the plane passing through the point -1,0,-2 and perpendicular to each of the planes 2x+y-z=2 and x-y-z=3 be ax+by+cz+8=0. Then the value of a+b+c is equal to:
HARD
JEE Main
IMPORTANT
Let a plane P pass through the point 3,7,-7 and contain the line, x-2-3=y-32=z+21. If distance of the plane P from the origin is d, then d2 is equal to
HARD
JEE Main
IMPORTANT
For real numbers α and β0, if the point of intersection of the straight lines x-α1=y-12=z-13 and x-4β=y-63=z-73 lies on the plane x+2y-z=8, then α-β is equal to :
MEDIUM
JEE Main
IMPORTANT
The distance of the point P3,4,4 from the point of intersection of the line joining the points Q3,-4,-5 and R2,-3,1 and the plane 2x+y+z=7, is equal to _____.
MEDIUM
JEE Main
IMPORTANT
If for a>0, the feet of perpendiculars from the points Aa,-2a,3 and B0,4,5 on the plane lx+my+nz=0 are points C0,-a,-1 and D respectively, then the length of line segment CD is equal to :
HARD
JEE Main
IMPORTANT
Let the position vectors of two points P and Q be 3i^-j^+2k^ and i^+2j^-4k^, respectively. Let R and S be two points such that the direction ratios of lines PR and QS are 4,-1,2 and -2,1,-2, respectively. Let lines PR and QS intersect at T. If the vector TA is perpendicular to both PR and QS and the length of vector TA is 5 units, then the modulus of a position vector of A is :
EASY
JEE Main
IMPORTANT
Let P be a plane lx+my+nz=0 containing the line, 1-x1=y+42=z+23. If plane P divides the line segment AB joining points A-3,-6,1 and B2,4,-3 in ratio k:1 then the value of k is equal to :