JEE Main · Mathematics ↓ Falling

Complex Numbers appeared 41 times across 3 years — 4.7% of Mathematics. This question is from De Moivre's Theorem.

Year 2026 2025 2024 Total
Questions 11 16 14 41

If z = √(3)2 + (i)/(2), i = √(-1), then (z²⁰¹ - i)⁸ is equal to

Solution & Explanation

Related Formula
eiθ = θ + i θ (r eiθ)ⁿ = rⁿ ei(nθ)
Core Logic

Represent z in polar form:

z = √(3)2 + i(1)/(2) = ((π)/(6)) + i ((π)/(6)) = eiπ/6

Calculate z²⁰¹:

z²⁰¹ = (eiπ/6)²⁰¹ = ei(201π/6) = ei(67π/2)
Step 1: Simplify Exponent
ei(67π/2) = ((67π)/(2)) + i ((67π)/(2))

Note that (67π)/(2) = 33π + (π)/(2).

(33π + (π)/(2)) = (odd multiple of π + (π)/(2)) = 0 (33π + (π)/(2)) = - ((π)/(2)) = -1

Thus, z²⁰¹ = -i.

Step 2: Final Calculation

Substitute z²⁰¹ into the expression:

(z²⁰¹ - i)⁸ = (-i - i)⁸ = (-2i)⁸ (-2)⁸ (i)⁸ = 256 × 1 = 256
Pattern Recognition

Convert standard coordinate complex numbers into Euler form immediately when large powers are present.

Chapter Mix

Class 11 Maths: 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_2026_23_january_evening

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