If z_1, z_2, z_3 in mathbbC$z_1, z_2, z_3 \in \mathbb{C}$ are the vertices of an equilateral triangle, whose centroid is z_0$z_0$, then sum_k=1^3 (z_k - z_0)^2$\sum_{k=1}^{3} (z_k - z_0)^2$ is equal to

### Related Formula For a quadratic equation Ax^2 + Bx + C = 0$Ax^2 + Bx + C = 0$, roots can be obtained via the quadratic formula: x = frac-B pm sqrtB^2 - 4AC2A$$x = \frac{-B \pm \sqrt{B^2 - 4AC}}{2A}$$ ### Core Logic Given quadratic equation: x^2-(3-2i)x-(2i-2)=0$$x^{2}-(3-2i)x-(2i-2)=0$$ Using the quadratic formula where A=1, B=-(3-2i), C=-(2i-2)$A=1, B=-(3-2i), C=-(2i-2)$: x = frac(3-2i) pm sqrt(3-2i)^2 - 4(1)(-(2i-2))2$$x = \frac{(3-2i) \pm \sqrt{(3-2i)^2 - 4(1)(-(2i-2))}}{2}$$ ### Step 1: Simplify the Discriminant textDiscriminant D = (3-2i)^2 + 4(2i-2)$$\text{Discriminant } D = (3-2i)^2 + 4(2i-2)$$ D = (9 - 4 - 12i) + (8i - 8)$$D = (9 - 4 - 12i) + (8i - 8)$$ D = 5 - 12i + 8i - 8 = -3 - 4i$$D = 5 - 12i + 8i - 8 = -3 - 4i$$ We need to find sqrt-3-4i$\sqrt{-3-4i}$. Let it be written as a perfect square: -3-4i = 1 - 4 - 4i = 1^2 + (2i)^2 - 2(1)(2i) = (1-2i)^2$$-3-4i = 1 - 4 - 4i = 1^2 + (2i)^2 - 2(1)(2i) = (1-2i)^2$$ Thus, sqrtD = pm(1-2i)$\sqrt{D} = \pm(1-2i)$. ### Step 2: Find the Roots Boxedx = frac(3-2i) pm (1-2i)2$Boxed{x = \frac{(3-2i) \pm (1-2i)}{2}}$ Case 1 (+ sign): x_1 = frac3 - 2i + 1 - 2i2 = frac4 - 4i2 = 2 - 2i$$x_1 = \frac{3 - 2i + 1 - 2i}{2} = \frac{4 - 4i}{2} = 2 - 2i$$ Case 2 (- sign): x_2 = frac3 - 2i - 1 + 2i2 = frac22 = 1 + 0i$$x_2 = \frac{3 - 2i - 1 + 2i}{2} = \frac{2}{2} = 1 + 0i$$ Let the roots be alpha + ibeta = 2 - 2i implies alpha=2, beta=-2$\alpha + i\beta = 2 - 2i \implies \alpha=2, \beta=-2$ and gamma + idelta = 1 + 0i implies gamma=1, delta=0$\gamma + i\delta = 1 + 0i \implies \gamma=1, \delta=0$ ### Step 3: Evaluate Target Expression alphagamma + betadelta = (2)(1) + (-2)(0) = 2$$\alpha\gamma + \beta\delta = (2)(1) + (-2)(0) = 2$$ ### Pattern Recognition Always try to express the complex number under the square root in the form (a + bi)^2$(a + bi)^2$ by matching the imaginary part 2ab = -4i implies ab = -2$2ab = -4i \implies ab = -2$, and a^2 - b^2 = -3$a^2 - b^2 = -3$. This avoids long calculations. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Mathematics: Complex Numbers and Quadratic Equations

### Related Formula textMinimum distance between two circles: d_min = C_1C_2 - r_1 - r_2$$\text{Minimum distance between two circles: } d_{\min} = C_1C_2 - r_1 - r_2$$ ### Core Logic The expressions define two circular disc fields in the complex plane: Circle 1: Center C_1(8, 2)$C_1(8, 2)$, radius r_1 = 1$r_1 = 1$ Circle 2: Center C_2(2, -6)$C_2(2, -6)$, radius r_2 = 2$r_2 = 2$

### Step 1: Calculate Center Distance Using coordinate distance formulation: C_1C_2 = sqrt(8 - 2)^2 + (2 - (-6))^2 = sqrt6^2 + 8^2 = 10$$C_1C_2 = \sqrt{(8 - 2)^2 + (2 - (-6))^2} = \sqrt{6^2 + 8^2} = 10$$ ### Step 2: Find Minimum Separation |z_1 - z_2|_min = C_1C_2 - r_1 - r_2 = 10 - 1 - 2 = 7$$|z_1 - z_2|_{\min} = C_1C_2 - r_1 - r_2 = 10 - 1 - 2 = 7$$ ### Pattern Recognition Always interpret modulus circle properties geometrically rather than algebraically. Disconnecting complex plane variables into simple 2D analytical geometry centers avoids calculation mistakes entirely. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Mathematics: Complex Numbers Class 11 Mathematics: Coordinate Geometry

### Related Formula For a complex number z = x + iy$z = x + iy$: 1. |z| = sqrtx^2 + y^2$|z| = \sqrt{x^2 + y^2}$ 2. z + overlinez = 2x$z + \overline{z} = 2x$ 3. z - overlinez = 2iy$z - \overline{z} = 2iy$ ### Core Logic Let z = x + iy$z = x + iy$. The first condition |z - 1| = 1$|z - 1| = 1$ describes a circle: (x-1)^2 + y^2 = 1 quad implies (1) $$(x-1)^{2} + y^{2} = 1 \quad \implies (1) $$ The second condition gives a straight line: (sqrt2-1)(2x) - i(2iy) = 2sqrt2$$(\sqrt{2}-1)(2x) - i(2iy) = 2\sqrt{2}$$ 2(sqrt2-1)x + 2y = 2sqrt2$$2(\sqrt{2}-1)x + 2y = 2\sqrt{2}$$ (sqrt2-1)x + y = sqrt2 quad implies (2) $$(\sqrt{2}-1)x + y = \sqrt{2} \quad \implies (2) $$ The set S$S$ contains the intersection points of this circle and line. ### Step 1: Solve for Intersection Points From (2), y = sqrt2 - (sqrt2-1)x$y = \sqrt{2} - (\sqrt{2}-1)x$. Substitute this into (1): (x-1)^2 + [sqrt2 - (sqrt2-1)x]^2 = 1$$(x-1)^2 + [\sqrt{2} - (\sqrt{2}-1)x]^2 = 1$$ Solving this quadratic equation gives two values of x$x$: x = 1 quad textor quad x = frac12-sqrt2 $$x = 1 \quad \text{or} \quad x = \frac{1}{2-\sqrt{2}} $$ - **Case A**: x = 1 implies y = sqrt2 - (sqrt2-1)(1) = 1$x = 1 \implies y = \sqrt{2} - (\sqrt{2}-1)(1) = 1$. So, one point is z_A = 1 + i$z_A = 1 + i$. Its magnitude is |z_A| = sqrt1^2 + 1^2 = sqrt2$|z_A| = \sqrt{1^2 + 1^2} = \sqrt{2}$. - **Case B**: x = frac12-sqrt2 = frac2+sqrt22 = 1 + frac1sqrt2$x = \frac{1}{2-\sqrt{2}} = \frac{2+\sqrt{2}}{2} = 1 + \frac{1}{\sqrt{2}}$. Then y = sqrt2 - (sqrt2-1)left(1+frac1sqrt2right) = sqrt2 - left(sqrt2 + 1 - 1 - frac1sqrt2right) = frac1sqrt2$y = \sqrt{2} - (\sqrt{2}-1)\left(1+\frac{1}{\sqrt{2}}\right) = \sqrt{2} - \left(\sqrt{2} + 1 - 1 - \frac{1}{\sqrt{2}}\right) = \frac{1}{\sqrt{2}}$. So, the other point is z_B = left(1 + frac1sqrt2right) + fracisqrt2$z_B = \left(1 + \frac{1}{\sqrt{2}}\right) + \frac{i}{\sqrt{2}}$. Its magnitude is |z_B| = sqrtleft(1+frac1sqrt2right)^2 + left(frac1sqrt2right)^2 = sqrt1 + sqrt2 + frac12 + frac12 = sqrt2 + sqrt2$|z_B| = \sqrt{\left(1+\frac{1}{\sqrt{2}}\right)^2 + \left(\frac{1}{\sqrt{2}}\right)^2} = \sqrt{1 + \sqrt{2} + \frac{1}{2} + \frac{1}{2}} = \sqrt{2 + \sqrt{2}}$. ### Step 2: Evaluate Min and Max Magnitude Expressions Comparing magnitudes, |z_B| > |z_A|$|z_B| > |z_A|$, so: z_1 = z_B = left(1 + frac1sqrt2right) + fracisqrt2 $$z_1 = z_B = \left(1 + \frac{1}{\sqrt{2}}\right) + \frac{i}{\sqrt{2}} $$ z_2 = z_A = 1 + i $$z_2 = z_A = 1 + i $$ Now, calculate |sqrt2z_1-z_2|^2$|\sqrt{2}z_{1}-z_{2}|^{2}$: sqrt2z_1 = sqrt2left(1 + frac1sqrt2right) + sqrt2left(fracisqrt2right) = (sqrt2 + 1) + i$$\sqrt{2}z_1 = \sqrt{2}\left(1 + \frac{1}{\sqrt{2}}\right) + \sqrt{2}\left(\frac{i}{\sqrt{2}}\right) = (\sqrt{2} + 1) + i$$ sqrt2z_1 - z_2 = (sqrt2 + 1 + i) - (1 + i) = sqrt2 $$\sqrt{2}z_1 - z_2 = (\sqrt{2} + 1 + i) - (1 + i) = \sqrt{2} $$ |sqrt2z_1 - z_2|^2 = |sqrt2|^2 = 2 $$|\sqrt{2}z_1 - z_2|^2 = |\sqrt{2}|^2 = 2 $$ ### Pattern Recognition Sees: Geometric constraint mapping to a circle and line intersection in the complex plane. Shortcut: Rationalizing terms like frac12-sqrt2$\frac{1}{2-\sqrt{2}}$ immediately into standard form 1+frac1sqrt2$1+\frac{1}{\sqrt{2}}$ saves you from handling layered fraction algebra down the line. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Complex Numbers: Geometry Class 10 Coordinate Geometry: Lines and Circles

### Related Formula For a complex coordinate transformation, substituting z = x + iy$z = x + iy$ and its conjugate overlinez = x - iy$\overline{z} = x - iy$ maps a complex condition directly into rectangular Cartesian coordinates. ### Core Logic Let's translate the complex set properties into Cartesian geometry: - Set P$P$: |z - (-2 + 3i)| le 1 implies$|z - (-2 + 3i)| \le 1 \implies$ Interior and boundary of a circle with center C(-2, 3)$C(-2, 3)$ and radius r = 1$r = 1$. - Set Q$Q$: (x+iy)(1+i) + (x-iy)(1-i) le -8 implies (x - y + ix + iy) + (x - y - ix - iy) le -8$(x+iy)(1+i) + (x-iy)(1-i) \le -8 \implies (x - y + ix + iy) + (x - y - ix - iy) \le -8$ 2(x - y) le -8 implies x - y + 4 le 0$$2(x - y) \le -8 \implies x - y + 4 \le 0$$ This defines a half-plane below or to the left of the boundary line L_2: x - y + 4 = 0$L_2: x - y + 4 = 0$. ### Step 1: Identify Extreme Points for Distance from Point A We want to find points in the region P cap Q$P \cap Q$ that minimize and maximize the distance to the external point A(3, -2)$A(3, -2)$, corresponding to |z - (3 - 2i)|$|z - (3 - 2i)|$. The line L_1$L_1$ connecting center C(-2, 3)$C(-2, 3)$ and point A(3, -2)$A(3, -2)$ has slope: m = frac-2 - 33 - (-2) = frac-55 = -1$$m = \frac{-2 - 3}{3 - (-2)} = \frac{-5}{5} = -1$$ Equation of line L_1$L_1$: y - 3 = -1(x + 2) implies x + y - 1 = 0$y - 3 = -1(x + 2) \implies x + y - 1 = 0$.

### Step 2: Calculate Coordinates for z1 and z2 - **Minimum Distance Point (z_2$z_2$):** By geometric observation, the minimum distance from A$A$ to the bounded region is the intersection point of lines L_1$L_1$ and L_2$L_2$: x - y + 4 = 0 quad textand quad x + y - 1 = 0 implies 2x + 3 = 0 implies x = -frac32, \, y = frac52$$x - y + 4 = 0 \quad \text{and} \quad x + y - 1 = 0 \implies 2x + 3 = 0 \implies x = -\frac{3}{2}, \, y = \frac{5}{2}$$ So, z_2 = left(-frac32, frac52 ight)$z_2 = \left(-\frac{3}{2}, \frac{5}{2} ight)$. - **Maximum Distance Point (z_1$z_1$):** The maximum distance is at the far boundary edge of the circle along line L_1$L_1$. The vector path from C(-2, 3)$C(-2, 3)$ opposite to A$A$ has unit direction left(-frac1sqrt2, frac1sqrt2right)$\left(-\frac{1}{\sqrt{2}}, \frac{1}{\sqrt{2}}\right)$: z_1 = left(-2 - frac1sqrt2, \, 3 + frac1sqrt2right)$$z_1 = \left(-2 - \frac{1}{\sqrt{2}}, \, 3 + \frac{1}{\sqrt{2}}\right)$$ ### Step 3: Evaluate Magnitudes and Sum Parameters Calculate the squares of the moduli: |z_1|^2 = left(-2 - frac1sqrt2right)^2 + left(3 + frac1sqrt2right)^2 = 4 + 2sqrt2 + frac12 + 9 + 3sqrt2 + frac12 = 14 + 5sqrt2$$|z_1|^2 = \left(-2 - \frac{1}{\sqrt{2}}\right)^2 + \left(3 + \frac{1}{\sqrt{2}}\right)^2 = 4 + 2\sqrt{2} + \frac{1}{2} + 9 + 3\sqrt{2} + \frac{1}{2} = 14 + 5\sqrt{2}$$ |z_2|^2 = left(-frac32right)^2 + left(frac52 ight)^2 = frac94 + frac254 = frac344 = frac172$$|z_2|^2 = \left(-\frac{3}{2}\right)^2 + \left(\frac{5}{2} ight)^2 = \frac{9}{4} + \frac{25}{4} = \frac{34}{4} = \frac{17}{2}$$ Now compute the total requested term: |z_1|^2 + 2|z_2|^2 = (14 + 5sqrt2) + 2left(frac172right) = 14 + 5sqrt2 + 17 = 31 + 5sqrt2$$|z_1|^2 + 2|z_2|^2 = (14 + 5\sqrt{2}) + 2\left(\frac{17}{2}\right) = 14 + 5\sqrt{2} + 17 = 31 + 5\sqrt{2}$$ Matching with alpha + betasqrt2$\alpha + \beta\sqrt{2}$ gives alpha = 31$\alpha = 31$ and beta = 5$\beta = 5$. Thus: alpha + beta = 31 + 5 = 36$$\alpha + \beta = 31 + 5 = 36$$ ### Pattern Recognition Sees: Locus intersection involving geometric complex inequalities. Shortcut: Translating complex equations into standard 2D graphs reveals the geometry instantly, mapping extreme distances to line intersections or boundary nodes cleanly. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Complex Numbers: Geometry Class 11 Coordinate Geometry: Straight Lines

### Related Formula For z = x + iy$z = x + iy$, modulus r = sqrtx^2 + y^2$r = \sqrt{x^2 + y^2}$ and argument theta$\theta$ depends on the quadrant location. ### Core Logic Given z = 2 - ileft(2 tan frac5pi8right)$z = 2 - i\left(2 \tan \frac{5\pi}{8}\right)$. Note that frac5pi8$\frac{5\pi}{8}$ lies in the second quadrant, so tan frac5pi8 < 0$\tan \frac{5\pi}{8} < 0$. Let's write r$r$: r = sqrt2^2 + left(-2 tan frac5pi8right)^2 = 2 sqrt1 + tan^2 frac5pi8 = 2 left| sec frac5pi8 right|$$r = \sqrt{2^2 + \left(-2 \tan \frac{5\pi}{8}\right)^2} = 2 \sqrt{1 + \tan^2 \frac{5\pi}{8}} = 2 \left| \sec \frac{5\pi}{8} \right|$$ Since sec frac5pi8$\sec \frac{5\pi}{8}$ is negative: r = -2 sec frac5pi8 = -2 sec left(pi - frac3pi8right) = 2 sec frac3pi8$$r = -2 \sec \frac{5\pi}{8} = -2 \sec \left(\pi - \frac{3\pi}{8}\right) = 2 \sec \frac{3\pi}{8}$$ ### Step 1: Finding the Amplitude Since x = 2 > 0$x = 2 > 0$ and y = -2 tan frac5pi8 > 0$y = -2 \tan \frac{5\pi}{8} > 0$, the complex number lies in the first quadrant. theta = tan^-1 left( fracyx right) = tan^-1 left( frac-2 tan frac5pi82 right) = tan^-1 left( -tan frac5pi8 right)$$\theta = \tan^{-1} \left( \frac{y}{x} \right) = \tan^{-1} \left( \frac{-2 \tan \frac{5\pi}{8}}{2} \right) = \tan^{-1} \left( -\tan \frac{5\pi}{8} \right)$$ -tan frac5pi8 = -tan left(pi - frac3pi8right) = tan frac3pi8$$-\tan \frac{5\pi}{8} = -\tan \left(\pi - \frac{3\pi}{8}\right) = \tan \frac{3\pi}{8}$$ theta = tan^-1 left( tan frac3pi8 right) = frac3pi8$$\theta = \tan^{-1} \left( \tan \frac{3\pi}{8} \right) = \frac{3\pi}{8}$$ ### Pattern Recognition Always absolute-value trigonometric terms coming out of square roots (e.g., sqrtsec^2 phi = |sec phi|$\sqrt{\sec^2 \phi} = |\sec \phi|$). Knowing the precise quadrant prevents incorrect signs. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Mathematics: Complex Numbers and Quadratic Equations