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Find the image of the point (3hati-hatj+...

Find the image of the point `(3hati-hatj+11hatk)` in the line `vecr = 2 hatj + 3hatk+lambda(2hati+3hatj+4hatk)`.

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To find the image of the point \( \vec{P} = 3\hat{i} - \hat{j} + 11\hat{k} \) in the line given by \( \vec{r} = 2\hat{j} + 3\hat{k} + \lambda(2\hat{i} + 3\hat{j} + 4\hat{k}) \), we can follow these steps: ### Step 1: Identify the Point and the Line The point \( \vec{P} \) can be expressed in coordinate form as \( (3, -1, 11) \). The line can be expressed in parametric form: - \( x = 2\lambda \) - \( y = 2 + 3\lambda \) - \( z = 3 + 4\lambda \) ### Step 2: Set Up the Midpoint Condition Let the image of the point \( \vec{P} \) be \( \vec{A} = (a, b, c) \). According to the midpoint theorem, the midpoint \( M \) between points \( \vec{P} \) and \( \vec{A} \) lies on the line. Therefore, we have: \[ M = \left( \frac{3 + a}{2}, \frac{-1 + b}{2}, \frac{11 + c}{2} \right) \] This midpoint \( M \) must satisfy the parametric equations of the line. ### Step 3: Equate the Midpoint to the Line From the line equations, we have: 1. \( \frac{3 + a}{2} = 2\lambda \) 2. \( \frac{-1 + b}{2} = 2 + 3\lambda \) 3. \( \frac{11 + c}{2} = 3 + 4\lambda \) ### Step 4: Solve for \( a, b, c \) in terms of \( \lambda \) From the first equation: \[ 3 + a = 4\lambda \implies a = 4\lambda - 3 \] From the second equation: \[ -1 + b = 4 + 6\lambda \implies b = 6\lambda + 5 \] From the third equation: \[ 11 + c = 6 + 8\lambda \implies c = 8\lambda - 5 \] ### Step 5: Find Direction Ratios of the Line Segment The direction ratios of the line segment \( \vec{PA} \) from \( \vec{P} \) to \( \vec{A} \) are: - \( a - 3 = 4\lambda - 6 \) - \( b + 1 = 6\lambda + 6 \) - \( c - 11 = 8\lambda - 16 \) ### Step 6: Set Up the Perpendicular Condition Since the line segment \( \vec{PA} \) is perpendicular to the line, their direction ratios must satisfy the dot product condition: \[ (2)(4\lambda - 6) + (3)(6\lambda + 6) + (4)(8\lambda - 16) = 0 \] ### Step 7: Simplify and Solve for \( \lambda \) Expanding the equation: \[ 8\lambda - 12 + 18\lambda + 18 + 32\lambda - 64 = 0 \] Combining like terms: \[ 58\lambda - 58 = 0 \implies \lambda = 1 \] ### Step 8: Substitute \( \lambda \) Back to Find \( a, b, c \) Substituting \( \lambda = 1 \): \[ a = 4(1) - 3 = 1 \] \[ b = 6(1) + 5 = 11 \] \[ c = 8(1) - 5 = 3 \] ### Step 9: Write the Image Point Thus, the image of the point \( \vec{P} \) is: \[ \vec{A} = 1\hat{i} + 11\hat{j} + 3\hat{k} \] ### Final Answer The image of the point \( (3\hat{i} - \hat{j} + 11\hat{k}) \) in the line is \( \vec{A} = \hat{i} + 11\hat{j} + 3\hat{k} \). ---
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NAGEEN PRAKASHAN ENGLISH-THREE-DIMENSIONAL GEOMETRY -Exercise 11 B
  1. Find the values of lambda ad mu if the points A(-1,4,-2),B(lambda,mu,1...

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  2. Find the equation of a line passes through the point hati+hatj+5hatk a...

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  3. The cartesian equation of a line is 6x+1=3y-2 = 3-2x. Find its directi...

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  4. Show that the line (x+3)/(2) = (y+1)/(-1) = (z+3)/(3) and (x)/(5) = (y...

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  5. Find the values of lambda if the following of lines perpendicular : ...

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  6. Show that the following pairs of lines intersect. Also find their poin...

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  7. Show that the lines (x-1)/(1) = (y-2)/(-1) = (z-1)/(1) and (x-1)/(1-...

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  8. Find the co-ordinates of that point at which the lines joining the poi...

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  9. Find the co-ordinates of that point at which the line joining the poin...

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  10. Find the co-ordinates of a point at which the line (x+1)/(2) = (y-3)/(...

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  11. Find the co-ordinates of a point at which the line (x+1)/(2) = (y-1)/(...

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  12. Find the co-ordiantes of the foot of perpendicular drawn from the poi...

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  13. Find the length and the foot of the perpendicular drawn from the point...

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  14. Find the co-ordinates of the foot of perpendicular and length of perp...

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  15. Find the image of the point (1,6,3) in the line x/1=(y-1)/2=(z-2)/3 . ...

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  16. Find the image of the point (0,2,3) in the line (x+3)/(5)= (y-1)/(2) =...

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  17. Find the image of the point (3hati-hatj+11hatk) in the line vecr = 2 h...

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  18. Find the shortest distance between the following lines : (i) vecr=4h...

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  19. Find the co-ordinates of the point at a distance of sqrt(5)units from ...

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  20. Find the co-ordinates of the point at a distance of sqrt(14) from the ...

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