Let a straight line LL pass through the point P(2,−1,3)P(2,-1{,}3) and be perpendicular to the lines x−14=y+14=z−32\frac{x-1}{4}=\frac{y+1}{4}=\frac{z-3}{2} and x−34=y−23=z+24\frac{x-3}{4}=\frac{y-2}{3}=\frac{z+2}{4}. If the line LL intersects the yzyz -plane at the point QQ, then the distance between the points PP and QQ is:

Answer: The distance between the points PP and QQ is 655\frac{6\sqrt{5}}{5}.

Step-by-step solution

Step 1: Find the direction vector of line L

The line LL is perpendicular to two given lines. The direction vectors of the given lines are d⃗1=⟨4,4,2⟩\vec{d}_{1} = \langle 4, 4, 2 \rangle and d⃗2=⟨4,3,4⟩\vec{d}_{2} = \langle 4, 3, 4 \rangle. The direction vector of line LL, denoted as dL⃗\vec{d_L}, must be perpendicular to both d⃗1\vec{d}_{1} and d⃗2\vec{d}_{2}. Therefore, dL⃗\vec{d_L} can be found by taking the cross product of d⃗1\vec{d}_{1} and d⃗2\vec{d}_{2}.

Step 2: Calculate the cross product

We calculate the determinant to find the components of the cross product. This gives us the direction vector dL⃗=⟨10,−8,−4⟩\vec{d_L} = \langle 10, -8, -4 \rangle. We can simplify this direction vector by dividing by a common factor of 2, so dL⃗=⟨5,−4,−2⟩\vec{d_L} = \langle 5, -4, -2 \rangle.

Step 3: Write the equation of line L

The line LL passes through the point P(2,−1,3)P(2, -1, 3) and has the direction vector dL⃗=⟨5,−4,−2⟩\vec{d_L} = \langle 5, -4, -2 \rangle. We can write the symmetric form of the equation of line LL using these values. We introduce a parameter λ\lambda to represent any point on the line.

Step 4: Find the point Q where L intersects the yz-plane

The yzyz -plane is defined by x=0x=0. We substitute x=0x=0 into the parametric equations of line LL to find the value of λ\lambda. Once λ\lambda is found, we substitute it back into the parametric equations to get the coordinates of point QQ.

Step 5: Calculate the distance between P and Q

Finally, we use the distance formula to find the distance between point P(2,−1,3)P(2, -1, 3) and point Q(0,35,195)Q\left(0, \frac{3}{5}, \frac{19}{5}\right). We substitute the coordinates into the formula and simplify the expression to get the final distance.

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