Let P=zin C:|z+2-3i|≤1$P=\{z\in\mathbb{C}:|z+2-3i|\le1\}$ and Q=zin C:z(1+i)+ z(1-i)≤-8$Q=\{z\in\mathbb{C}:z(1+i)+\overline{z}(1-i)\le-8\}$. Let in P Q, |z-3+2i|$P \cap Q, |z-3+2i|$ be maximum and minimum at z₁$z_{1}$ and z₂$z_{2}$ respectively. If |z₁|²+2|z₂|²=α+β√(2)$|z_{1}|^{2}+2|z_{2}|^{2}=\alpha+\beta\sqrt{2}$, where α, β$\alpha, \beta$ are integers, then α+β$\alpha+\beta$ equals
Numerical Answer Type:
Enter a numerical valueAnswer: 36 to 36+4 marks
Solution & Explanation
Related Formula
For a complex coordinate transformation, substituting z = x + iy$z = x + iy$ and its conjugate z = 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)| ≤ 1$|z - (-2 + 3i)| \le 1 \implies$ 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) ≤ -8 (x - y + ix + iy) + (x - y - ix - iy) ≤ -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) ≤ -8 x - y + 4 ≤ 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 L₂: 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 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 L₁$L_1$ connecting center C(-2, 3)$C(-2, 3)$ and point A(3, -2)$A(3, -2)$ has slope:
Equation of line L₁$L_1$: y - 3 = -1(x + 2) x + y - 1 = 0$y - 3 = -1(x + 2) \implies x + y - 1 = 0$.
The graphic details the intersection region bounded by the circular locus and the line inequality, showing points z1 and z2 relative to external reference point P.
Step 2: Calculate Coordinates for z₁$z_1$ and z₂$z_2$
Minimum Distance Point (z₂$z_2$): By geometric observation, the minimum distance from A$A$ to the bounded region is the intersection point of lines L₁$L_1$ and L₂$L_2$:
x - y + 4 = 0 and x + y - 1 = 0 2x + 3 = 0 x = -(3)/(2), y = (5)/(2)$$x - y + 4 = 0 \quad \text{and} \quad x + y - 1 = 0 \implies 2x + 3 = 0 \implies x = -\frac{3}{2}, \, y = \frac{5}{2}$$
So, z₂ = (-(3)/(2), (5)/(2))$z_2 = \left(-\frac{3}{2}, \frac{5}{2}\right)$.
Maximum Distance Point (z₁$z_1$): The maximum distance is at the far boundary edge of the circle along line L₁$L_1$. The vector path from C(-2, 3)$C(-2, 3)$ opposite to A$A$ has unit direction (- 1√(2), 1√(2))$\left(-\frac{1}{\sqrt{2}}, \frac{1}{\sqrt{2}}\right)$:
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.
Chapter Mix
Class 11 Complex Numbers: Geometry
Class 11 Coordinate Geometry: Straight Lines
Keywords:#complex locus circle#half plane inequality intersection#maximum minimum distance geometry
More Complex Numbers Previous-Year Questions — Page 5
Q55jee_main_2025_04_april_eveningProperties of Complex Numbers
Let the product of ω₁ = (8 + i) θ + (7 + 4 i) θ$\omega_1 = (8 + \mathrm{i}) \sin \theta + (7 + 4 \mathrm{i}) \cos \theta$ and ω₂ = (1 + 8 i) θ + (4 + 7 i) θ$\omega_2 = (1 + 8 \mathrm{i}) \sin \theta + (4 + 7 \mathrm{i}) \cos \theta$ be α +iβ$\alpha +\mathrm{i}\beta$, i = √(-1)$\mathrm{i} = \sqrt{-1}$. Let p and q be the maximum and the minimum values of α +β$\alpha +\beta$ respectively.
A.140$140$
B.130$130$
C.160$160$
D.150$150$
Solution
Core Logic
Let's expand the terms by grouping real and imaginary parts explicitly:
Maximum value p = 65 + 60(1) = 125$$\text{Maximum value } p = 65 + 60(1) = 125$$Minimum value q = 65 + 60(-1) = 5$$\text{Minimum value } q = 65 + 60(-1) = 5$$
Sum of maximum and minimum bounds equals:
p + q = 125 + 5 = 130$$p + q = 125 + 5 = 130$$
Pattern Recognition
Observe the symmetric structure in complex variables: (u+iv)$(u+iv)$ and (v+iu)$(v+iu)$. Their product structurally completely cancels out the real component, saving you from a highly messy component expansion.
Chapter Mix
Class 11 Mathematics: Complex Numbers
Class 11 Mathematics: Trigonometric Functions
Q71jee_main_2025_04_april_eveningCube Roots of Unity
If α$\alpha$ is a root of the equation x² + x + 1 = 0$x^{2} + x + 1 = 0$ and Σk=1ⁿ(αk + 1αk)² = 20$\sum_{k=1}^{n}\left(\alpha^{k} + \frac{1}{\alpha^{k}}\right)^{2} = 20$, then n$n$ is equal to
Numerical Answer.Answer: 11 to 11
Solution
Core Logic
The equation x² + x + 1 = 0$x^2 + x + 1 = 0$ has complex roots which are the non-real cube roots of unity. Thus, we can set α = ω$\alpha = \omega$ (where ω³ = 1$\omega^3 = 1$ and 1 + ω + ω² = 0$1 + \omega + \omega^2 = 0$).
Let's analyze the general term block Tk = (ω^k + (1)/(ω^k))²$T_k = \left(\omega^k + \frac{1}{\omega^k}\right)^2$:
Because ω^k$\omega^k$ is periodic with period 3$3$, let's examine the values of Tk$T_k$ for different values of k$k$:
If k$k$ is a multiple of 3$3$ (k=3m$k=3m$): ω2k = 1, ω^k = 1 Tk = 1 + 1 + 2 = 4$\omega^{2k} = 1, \omega^k = 1 \implies T_k = 1 + 1 + 2 = 4$.
If k$k$ is not a multiple of 3$3$ (k=3m+1$k=3m+1$ or 3m+2$3m+2$): ω2k + ω^k = -1 Tk = -1 + 2 = 1$\omega^{2k} + \omega^k = -1 \implies T_k = -1 + 2 = 1$.
Step 1: Evaluating periodic blocks
Every block of three consecutive terms (k = 1, 2, 3$k = 1, 2, 3$) contributes exactly:
Sum of a block = 1 + 1 + 4 = 6$$\text{Sum of a block} = 1 + 1 + 4 = 6$$
We want the total summation to equal 20$20$. Let's divide 20$20$ by our block value 6$6$:
20 = 3 × 6 + 2$$20 = 3 \times 6 + 2$$
This means the sum must consist of 3$3$ full periodic blocks plus additional terms that add up to 2$2$.
Step 2: Determining the final term count n
The number of terms in 3$3$ full blocks is 3 × 3 = 9$3 \times 3 = 9$ terms, giving a sum of 18$18$.
To get the remaining value of 2$2$, we look at the next terms:
Term 10 (k=10$k=10$, not a multiple of 3) adds 1 Total = 18 + 1 = 19$1 \implies \text{Total} = 18 + 1 = 19$.
Term 11 (k=11$k=11$, not a multiple of 3) adds 1 Total = 19 + 1 = 20$1 \implies \text{Total} = 19 + 1 = 20$.
Hence, the series terminates exactly at n = 11$n = 11$.
Pattern Recognition
Whenever complex roots of unity or cyclic properties show up inside series sums, group terms into blocks based on the underlying period length (3$3$ here) to convert large sums into simple modular arithmetic arithmetic calculations.
Chapter Mix
Class 11 Mathematics: Complex Numbers
Class 11 Mathematics: Sequences and Series
Q73jee_main_2025_04_april_morningGeometry of Complex Numbers
Let A = z in C : |z - 2 - i| = 3$A = \{z \in \mathbb{C} : |z - 2 - i| = 3\}$, B = z in C : Re(z - iz) = 2$B = \{z \in \mathbb{C} : \operatorname{Re}(z - iz) = 2\}$ and S = A B$S = A \cap B$. Then Σz in S |z|²$\sum_{z \in S} |z|^2$ is equal to
Numerical Answer.Answer: 22 to 22
Solution
Related Formula
Magnitude squared representation:
|z|² = x² + y² for z = x + iy$$|z|^2 = x^2 + y^2 \quad \text{for } z = x + iy$$
Core Logic
Convert complex sets into Cartesian forms by setting z = x + iy$z = x + iy$:
Set A$A$: |(x-2) + i(y-1)| = 3 (x-2)² + (y-1)² = 9 (1)$|(x-2) + i(y-1)| = 3 \implies (x-2)^2 + (y-1)^2 = 9 \quad \dots (1)$
Set B$B$: z - iz = (x+iy) - i(x+iy) = (x+y) + i(y-x)$z - iz = (x+iy) - i(x+iy) = (x+y) + i(y-x)$.
Re(z - iz) = 2 x + y = 2 y = 2 - x (2)$\operatorname{Re}(z - iz) = 2 \implies x + y = 2 \implies y = 2 - x \quad \dots (2)$
Σz in S |z|² = 13 + 9 = 22$$\sum_{z \in S} |z|^2 = 13 + 9 = 22$$
Pattern Recognition
Avoid explicitly using radical root approximations. Summing symmetric expressions directly through standard Vieta coefficient sum shortcuts preserves clean fractions.
Chapter Mix
Class 11 Mathematics: Complex Numbers and Quadratic Equations
Q61jee_main_2025_07_april_eveningLocus of a Complex Number
If the locus of z in C$z \in C$, such that R e ( z - 12 z + i) + R e ( z - 12 z - i) = 2$\operatorname {R e} \left(\frac {z - 1}{2 z + \mathrm {i}}\right) + \operatorname {R e} \left(\frac {\bar {z} - 1}{2 \bar {z} - \mathrm {i}}\right) = 2$, is a circle of radius r$r$ and center (a, b)$(a, b)$ then (15ab)/(r²)$\frac{15ab}{r^2}$ is equal to:
A.24$24$
B.12$12$
C.18$18$
D.16$16$
Solution
Related Formula
For a complex number w$w$, Re(w) = Re( w)$\operatorname{Re}(w) = \operatorname{Re}(\bar{w})$. Hence:
Notice that z - 12 z - i$\frac{\bar{z} - 1}{2\bar{z} - i}$ is the exact complex conjugate of (z - 1)/(2z + i)$\frac{z - 1}{2z + i}$.
Thus, the given equation simplifies directly via complex identities to:
Symmetric rational polynomials in roots α, β$\alpha, \beta$ that can be split into identical numeric multipliers for αⁿ$\alpha^n$ and βⁿ$\beta^n$ allow direct cancellation of the polynomial bases without evaluating the individual roots explicitly.
Practice past-year questions one chapter at a time. Pick an exam → subject → chapter and get every PYQ for that topic — pulled together from all past papers — with the chapter's key formulas alongside.