Complex Numbers
ICSE · Class 11 · Mathematics
Flashcards for Complex Numbers — ICSE Class 11 Mathematics. Quick Q&A cards covering key concepts, definitions, and formulas.
Interactive on Super Tutor
Studying Complex Numbers? Get the full interactive chapter.
Quizzes, flashcards, AI doubt-solver and a step-by-step study plan — built for flashcards and more.
1,000+ Class 11 students started this chapter today

Learn better with visuals Super Tutor has hundreds of illustrations like this across every chapter — all free to try.
Get startedEvaluate: i^25
Answer
Step 1: Powers of i repeat every 4 terms: i, -1, -i, 1. Step 2: Divide 25 by 4. 25 = 4 × 6 + 1, so the remainder is 1. Step 3: Remainder 1 gives i. Answer: i…
Evaluate: i^-101
Answer
Step 1: Use the reciprocal rule for negative powers. i^-101 = 1 / i^101 Step 2: Reduce 101 by the 4-cycle. 101 = 4 × 25 + 1, so i^101 = i. Step 3: Therefore, i^-101 = 1 / i = -i Answer: -i…
Evaluate: sqrt(-100) + sqrt(-9)
Answer
Step 1: Write each negative square root using i. sqrt(-100) = 10i sqrt(-9) = 3i Step 2: Add the results. 10i + 3i = 13i Answer: 13i…
Evaluate: sqrt(-36) × sqrt(-49)
Answer
Step 1: Convert each square root. sqrt(-36) = 6i sqrt(-49) = 7i Step 2: Multiply. (6i)(7i) = 42i^2 Step 3: Use i^2 = -1. 42i^2 = -42 Answer: -42…
Evaluate: sqrt(-3) × sqrt(-5)
Answer
Step 1: Convert both roots. sqrt(-3) = i sqrt(3) sqrt(-5) = i sqrt(5) Step 2: Multiply. (i sqrt(3))(i sqrt(5)) = i^2 sqrt(15) Step 3: Use i^2 = -1. i^2 sqrt(15) = -sqrt(15) Answer: -sqrt(15)…
When do you use the rule sqrt(ab) = sqrt(a) × sqrt(b)?
Answer
Use it only when at least one of a and b is non-negative. Example: sqrt(4 × 9) = sqrt(4) × sqrt(9) = 2 × 3 = 6. It should not be used blindly for negative numbers under the root. Example check: sqrt(-…
Write i^n in a fast way for any integer n.
Answer
Use the 4-cycle of powers of i. i^0 = 1 If n > 0, divide n by 4 and use the remainder: remainder 0 → 1 remainder 1 → i remainder 2 → -1 remainder 3 → -i If n < 0, first convert it to a reciprocal and …
Solve for real a: 3i^3 - 2ai^2 + (1 - a)i + 5 is real.
Answer
Step 1: Simplify the powers of i. i^3 = -i and i^2 = -1 So, 3i^3 - 2ai^2 + (1 - a)i + 5 = 3(-i) - 2a(-1) + (1 - a)i + 5 = -3i + 2a + (1 - a)i + 5 = (2a + 5) + (-2 - a)i Step 2: For the number to be re…
+22 more flashcards available
Practice AllFrequently Asked Questions
What are the important topics in Complex Numbers for ICSE Class 11 Mathematics?
How to score full marks in Complex Numbers — ICSE Class 11 Mathematics?
How many flashcards are available for Complex Numbers?
Sources & Official References
Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.
More resources for Complex Numbers
Practice Quiz
Test yourself with a quick quiz
Important Questions
Practice with board exam-style questions
Revision Notes
Key points for last-minute revision
Formula Sheet
All formulas in one place
Chapter Summary
Understand the chapter at a glance
Concept Maps
See how topics connect visually
Study Plan
Step-by-step plan to ace this chapter
Syllabus
What topics to cover
NCERT Solutions
Every textbook question solved step by step
For serious students
Get the full Complex Numbers chapter — for free.
Quizzes, flashcards, AI doubt-solver and a step-by-step study plan for ICSE Class 11 Mathematics.