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If P(x,y,z) is a point on the line segme...

If `P(x,y,z)` is a point on the line segment joining `Q(2,2,4)` and `R(3,5,6)` such that projections of `vec(OP)` on the axes are `13/5,19/5,26/5` respectively, then `P` divides `QR` in the ratio

A

`1:2`

B

`3:2`

C

`2:3`

D

`3:1`

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The correct Answer is:
To solve the problem, we need to find the point \( P(x,y,z) \) that divides the line segment joining points \( Q(2,2,4) \) and \( R(3,5,6) \) in a certain ratio, given the projections of \( \vec{OP} \) on the axes. ### Step-by-Step Solution: 1. **Identify the Coordinates of Points Q and R**: - \( Q(2, 2, 4) \) - \( R(3, 5, 6) \) 2. **Determine the Coordinates of Point P**: - The coordinates of point \( P \) can be expressed in terms of the ratio \( \lambda : 1 \) as follows: \[ P(x, y, z) = \left( \frac{3\lambda + 2}{\lambda + 1}, \frac{5\lambda + 2}{\lambda + 1}, \frac{6\lambda + 4}{\lambda + 1} \right) \] 3. **Set Up the Equations Based on Projections**: - We know the projections of \( \vec{OP} \) on the axes are given as: \[ x = \frac{13}{5}, \quad y = \frac{19}{5}, \quad z = \frac{26}{5} \] - This gives us three equations: \[ \frac{3\lambda + 2}{\lambda + 1} = \frac{13}{5} \quad (1) \] \[ \frac{5\lambda + 2}{\lambda + 1} = \frac{19}{5} \quad (2) \] \[ \frac{6\lambda + 4}{\lambda + 1} = \frac{26}{5} \quad (3) \] 4. **Solve the First Equation**: - From equation (1): \[ 5(3\lambda + 2) = 13(\lambda + 1) \] \[ 15\lambda + 10 = 13\lambda + 13 \] \[ 2\lambda = 3 \implies \lambda = \frac{3}{2} \] 5. **Verify with the Other Equations**: - Substitute \( \lambda = \frac{3}{2} \) into equations (2) and (3) to verify: - For equation (2): \[ \frac{5(\frac{3}{2}) + 2}{\frac{3}{2} + 1} = \frac{\frac{15}{2} + 2}{\frac{5}{2}} = \frac{\frac{19}{2}}{\frac{5}{2}} = \frac{19}{5} \] - For equation (3): \[ \frac{6(\frac{3}{2}) + 4}{\frac{3}{2} + 1} = \frac{9 + 4}{\frac{5}{2}} = \frac{13}{\frac{5}{2}} = \frac{26}{5} \] - Both equations are satisfied. 6. **Determine the Ratio**: - Since \( \lambda = \frac{3}{2} \), the ratio in which \( P \) divides \( QR \) is: \[ \text{Ratio} = \lambda : 1 = \frac{3}{2} : 1 = 3 : 2 \] ### Final Answer: The point \( P \) divides the line segment \( QR \) in the ratio \( 3 : 2 \).

To solve the problem, we need to find the point \( P(x,y,z) \) that divides the line segment joining points \( Q(2,2,4) \) and \( R(3,5,6) \) in a certain ratio, given the projections of \( \vec{OP} \) on the axes. ### Step-by-Step Solution: 1. **Identify the Coordinates of Points Q and R**: - \( Q(2, 2, 4) \) - \( R(3, 5, 6) \) ...
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OBJECTIVE RD SHARMA-THREE DIMENSIONAL COORDINATE SYSTEM -Exercise
  1. If P(x,y,z) is a point on the line segment joining Q(2,2,4) and R(3,5,...

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  2. If the x-coordinate of a point P on the join of Q(2,2,1) and R(5,1,-2)...

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  3. The distance of the point P(a,b,c) from the x-axis is

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  4. Ratio in which the xy-plane divides the joint of (1,2,3) and (4,2,1), ...

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  5. If P(3,2,-4),Q(5,4,-6) and R(9,8,-10) are collinear, then R divides PQ...

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  6. A(3,2,0),B(5,3,2),(-9,6,-3) are the vertices of /\ ABC and AD is the b...

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  7. A line passes through the points (6,-7,-1)a n d(2,-3,1)dot Find te ...

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  8. If a line makes angles alpha,beta,gamma with the positive direction of...

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  9. If P is a point in space such that OP=12 and vec(OP) is inclied at ang...

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  10. A vector vec O P is inclined to O Xa t45^0a n dO Ya t60^0 . Find the ...

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  11. A vector vecr is equally inclined with the coordinates axes. If the ti...

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  12. If vecr is a vector of magnitude 21 and has direction ratios proporti...

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  13. The direction cosines of the lines bisecting the angle between the lin...

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  14. Find the coordinates of the foot of the perpendicular drawn from po...

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  15. The foot of the perpendicular drawn from a point with position vector ...

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  16. The projections of a directed line segment on the coordinate axes are ...

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  17. Let l1,m1,n1; l2,m2,n2 and l3,m3,n3 be the direction cosines of three ...

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  18. If P(x ,y ,z) is a point on the line segment joining Q(2,2,4)a n d ...

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  19. If O is the origin, O P=3 with direction ratios -1,2,a n d-2, then fin...

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  20. A mirror and a source of light are situated at the origin O and at ...

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  21. Find the angel between any two diagonals of a cube.

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