A line passing through the point P(a,θ)P(a, \theta) makes an acute angle α\alpha with the positive x-axis. Let this line be rotated about the point P through an angle α2\frac{\alpha}{2} in the clockwise direction. If in the new position, the slope of the line is 2−32 - \sqrt{3} and its distance from the origin is 12\frac{1}{\sqrt{2}}, then the value of 3a2tan⁡2α−233a^2 \tan^2 \alpha - 2\sqrt{3} is:

Answer: The problem is underdetermined. The value of 3a2tan⁡2α−233a^2 \tan^2 \alpha - 2\sqrt{3} simplifies to a2−23a^2 - 2\sqrt{3}. However, the value of aa cannot be uniquely determined from the given information because the point P(a,θ)P(a, \theta) is given in polar coordinates, but the line equation is derived using P(a,θ)P(a, \theta) as Cartesian coordinates (a,θ)(a, \theta). If P(a,θ)P(a, \theta) were Cartesian coordinates, then aa would be the x-coordinate and θ\theta would be the y-coordinate. If P(a,θ)P(a, \theta) were polar coordinates, then aa would be the radial distance and θ\theta would be the angle, in which case the Cartesian coordinates would be (acos⁡θ,asin⁡θ)(a\cos\theta, a\sin\theta). Without clarification on the nature of P(a,θ)P(a, \theta), a unique numerical answer for aa (and thus the expression) cannot be found.

Step-by-step solution

Step 1: Determine the initial and final angles of the line

The initial line makes an angle α\alpha with the positive xx -axis, so its slope is m1=tan⁡αm_1 = \tan \alpha. When the line is rotated clockwise by α2\frac{\alpha}{2}, its new angle with the positive xx -axis becomes α−α2=α2\alpha - \frac{\alpha}{2} = \frac{\alpha}{2}. Therefore, the slope of the new line is m2=tan⁡(α2)m_2 = \tan \left( \frac{\alpha}{2} \right).

Step 2: Find the value of α

We are given that the slope of the new line is 2−32 - \sqrt{3}. We know that tan⁡15∘=2−3\tan 15^\circ = 2 - \sqrt{3}. Therefore, α2=15∘\frac{\alpha}{2} = 15^\circ, which implies α=30∘\alpha = 30^\circ.

Step 3: Determine the equation of the new line

The new line passes through the point P(a,θ)P(a, \theta) and has a slope of 2−32 - \sqrt{3}. Using the point-slope form of a line, y−y1=m(x−x1)y - y_1 = m(x - x_1), we get the equation of the line.

Step 4: Use the distance from the origin to find 'a'

The distance of a line Ax+By+C=0Ax + By + C = 0 from the origin is given by ∣C∣A2+B2\frac{|C|}{\sqrt{A^2 + B^2}}. Substituting the values from our line equation, we can simplify the denominator. Note that 8−43=2(4−23)=2(3−1)\sqrt{8 - 4\sqrt{3}} = \sqrt{2(4 - 2\sqrt{3})} = \sqrt{2}(\sqrt{3} - 1).

Step 5: Evaluate the expression

We need to find the value of 3a2tan⁡2α−233a^2 \tan^2 \alpha - 2\sqrt{3}. We already found α=30∘\alpha = 30^\circ. Substituting this value, we get tan⁡30∘=13\tan 30^\circ = \frac{1}{\sqrt{3}}. The expression simplifies to a2−23a^2 - 2\sqrt{3}.

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