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Complex Numbers appeared 41 times across 3 years — 4.7% of Mathematics. This question is from Roots of Quadratic Equations in Complex Fields.

Year 2026 2025 2024 Total
Questions 11 16 14 41

Let zin C be such that (z² + 3i)/(z - 2 + i) = 2 + 3i[cite: 627, 629]. Then the sum of all possible values of z² is[cite: 630]:

Solution & Explanation

Related Formula

For a quadratic system equation az²+bz+c=0 with roots z₁, z₂:

  • z₁ + z₂ = -b/a
  • z₁ z₂ = c/a
  • z₁² + z₂² = (z₁+z₂)² - 2z₁z₂
Core Logic

Cross-multiply the denominators to configure a linear equation layout [cite: 1355]: z² + 3i = (z - 2 + i)(2 + 3i) [cite: 1355] z² + 3i = z(2 + 3i) + (-2 + i)(2 + 3i) [cite: 1355] z² + 3i = z(2 + 3i) - 4 - 6i + 2i - 3 = z(2 + 3i) - 7 - 4i [cite: 1355]

Formulate the classic quadratic representation layout [cite: 1356]: z² - z(2 + 3i) + 7 + 7i = 0 [cite: 1356]

Step 1: Summing the squared roots

Identify coefficients from the structural template [cite: 1357]:

z₁ + z₂ = 2 + 3i z₁ z₂ = 7 + 7i

Evaluate sum of possible squared values (z₁² + z₂²) [cite: 1357]: z₁² + z₂² = (z₁ + z₂)² - 2z₁ z₂ [cite: 1357] = (2 + 3i)² - 2(7 + 7i) [cite: 1357] = (4 - 9 + 12i) - (14 + 14i) = -5 + 12i - 14 - 14i [cite: 1357] = -19 - 2i [cite: 1358]

Pattern Recognition

The question asks for the sum of values of z², meaning z₁² + z₂². Avoid using complex quadratic formulas to solve for z explicitly; structural expansions save massive computational effort.

Chapter Mix

Class 11 Mathematics: Complex Numbers

Reference Study Guides

More Complex Numbers Previous-Year Questions — Page 9

Q26 jee_main_2024_31_jan_morning Properties of Modulus and Argument
If α denotes the number of solutions of |1 - i|^x = 2^x and β = ((|z|)/( (z))), where z = (π)/(4) (1 + i)⁴ ( 1 - √(π) i√(π) + i + √(π) - i1 + √(π) i), i = √(-1), then the distance of the point (α, β) from the line 4x - 3y = 7 is
Numerical Answer. Answer: 3 to 3

Solution

Core Logic
|1 - i|^x = 2^x (√(2))^x = 2^x 2x/2 = 2^x

This implies (x)/(2) = x x = 0. There is exactly 1 solution, so α = 1.

Step 1: Simplify complex number z
(1+i)⁴ = ((1+i)²)² = (1 + i² + 2i)² = (2i)² = -4

Thus, z = -π ( (1-√(π)i)(√(π)-i)π + 1 + (√(π)-i)(1-√(π)i)1 + π )

Step 2: Simplify Bracket

Let's expand the terms directly: z = (π)/(4)(-4) [ √(π) - π i - i - √(π)π + 1 + √(π) - i - π i - √(π)1 + π ]

= -π [ (-i(π+1))/(π+1) + (-i(π+1))/(π+1) ] = -π [ -i - i ] = 2π i
Step 3: Find beta

For z = 2π i: |z| = 2π and (z) = (π)/(2).

β = (|z|)/( (z)) = (2π)/(π/2) = 4
Step 4: Distance from Line

Distance of point (α, β) = (1, 4) from the line 4x - 3y - 7 = 0:

D = |4(1) - 3(4) - 7|√(4² + (-3)²) = (|4 - 12 - 7|)/(5) = (|-15|)/(5) = 3
Chapter Mix

Class 11 Maths: Complex Numbers and Quadratic Equations Class 11 Maths: Straight Lines

More Complex Numbers Questions — jee_main_2025_03_april_morning

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