These class 11 maths handwritten notes chapter 4 complex numbers and quadratic equations have been carefully prepared for quick, one-shot revision before your CBSE Boards, JEE Main, JEE Advanced and CUET exams. Every page is written by hand with boxed formulas and a clear Argand plane diagram, according to the latest 2026-27 CBSE syllabus.

RV

Rohit Verma ✓ Verified by Collegedunia

M.Sc. Mathematics, 8 years of CBSE Class 11 and 12 Maths teaching. These notes are written and proofread by hand.

Complex Numbers and Quadratic Equations is the chapter where the number system grows past the real line. These handwritten pages turn the whole chapter into neat, colour-coded notes you can revise in one sitting.

  • Boxed formulas for the modulus, conjugate and polar form, ready to copy onto the answer sheet.
  • A hand-drawn Argand plane that shows exactly where a complex number sits.
  • Pairs with the NCERT Solutions, Notes and Book PDF linked lower on this page.

What the Complex Numbers and Quadratic Equations Handwritten Notes Cover

The notes open with the imaginary unit i, where i squared equals minus one. They then move through the full chapter in the same order as the NCERT textbook, so nothing is missed. Each new sub-topic is written in red ink so students can find it fast during revision.

  • Complex numbers: the form a + bi, with the real part a and the imaginary part b.
  • Algebra: adding, subtracting, multiplying and dividing complex numbers step by step.
  • Modulus and conjugate: the size of a number and its mirror across the real axis.
  • Argand plane and polar form: plotting z and writing it using r and the angle theta.
  • Quadratic equations: solving equations whose roots are complex.

Because these class 11 maths handwritten notes chapter 4 complex numbers and quadratic equations keep every rule inside a box, the eye jumps straight to the point. This makes them ideal for a last, fast recap the night before a test.

Key Formulas and Diagrams in the Complex Numbers Notes

The core of the chapter is a small set of formulas and the Argand diagram that ties them together. The notes keep these on one page. The table below lists the formulas the pages box in colour.

IdeaFormula
Imaginary uniti2 = −1, so √(−1) = i
Modulus of z = a + bi|z| = √(a2 + b2)
Conjugate of z = a + biz̅ = a − bi, with z × z̅ = |z|2
Polar formz = r(cos θ + i sin θ), where r = |z|
Roots of ax2 + bx + c = 0x = (−b ± √(b2 − 4ac)) / 2a

The Argand plane is drawn once and reused. The real part is measured along the horizontal axis and the imaginary part up the vertical axis, so every complex number becomes a single point that makes the modulus and angle easy to recall.

How to Use These Handwritten Notes for Revision

Handwritten notes work best as a final layer of revision, not as your first read. The plan below helps students get the most out of the Complex Numbers and Quadratic Equations handwritten notes in the run-up to the exam. Follow it once a week and again the day before the test.

  • First pass: read the pages once, following the i-to-polar-form order.
  • Active recall: cover each boxed formula and write it from memory.
  • Draw it: plot two complex numbers on the Argand plane yourself.
  • Self-test: solve one quadratic with a negative discriminant to lock in complex roots.

Because the class 11 maths handwritten notes chapter 4 complex numbers and quadratic equations come as a downloadable PDF, students can save them on a phone and revise offline on the way to the exam centre. Pair these pages with the full NCERT Solutions to check your written answers.

Student Feedback on the Complex Numbers Handwritten Notes

Student Feedback: In a Collegedunia poll of 12,840 Class 11 Maths students before the 2026 boards, 76% of students said the boxed conjugate and modulus rules made division of complex numbers far easier to recall. Most students marked the polar form as the point they revised last before the exam.

Source: 2026-27 Class 11 Mathematics student poll. Sample of 12,840 students from CBSE schools across 14 states.

Other Complex Numbers Class 11 Maths Resources

These handwritten notes are a revision layer. To prepare fully, students should use them with the other resources for the same chapter, linked below. Read the notes, test yourself with the solutions, then open the book PDF for the original text.

ResourceBest used for
Complex Numbers Class 11 NCERT SolutionsStep-by-step answers to every back-exercise question
Complex Numbers Class 11 NotesFull chapter summary with all definitions and formulas in one place
Complex Numbers NCERT Book PDFReading the original NCERT chapter text and examples

Tip: revise the conjugate rule first, then divide one complex number using it. That single link fixes most division sums.

All Class 11 Maths Handwritten Notes by Chapter

The table links the handwritten notes for every chapter of Class 11 Maths, so students can move across the course in one click. Complex Numbers and Quadratic Equations is highlighted.

FAQs on Complex Numbers and Quadratic Equations Handwritten Notes

Complex Numbers and Quadratic Equations Handwritten Notes - Frequently Asked Questions

Ques. Are these class 11 maths handwritten notes chapter 4 complex numbers and quadratic equations free to download?

Ans. Yes. The Complex Numbers and Quadratic Equations handwritten notes are free to download as a PDF from this page. They follow the 2026-27 CBSE syllabus and cover the full chapter in boxed, colour-coded pages for quick revision.

Ques. What topics do the Complex Numbers handwritten notes cover?

Ans. They cover the imaginary unit i, complex numbers in a + bi form, addition, subtraction, multiplication and division, the modulus and conjugate, the Argand plane, polar form, and solving quadratic equations with complex roots.

Ques. Which formulas should I revise first in Complex Numbers?

Ans. Start with i squared equals minus one, then the modulus |z| = square root of (a squared plus b squared) and the conjugate a minus bi. After that learn the polar form and the quadratic formula, which the notes box in colour.

Ques. Are these notes enough for the Class 11 Complex Numbers exam?

Ans. They are a strong final revision layer. For full preparation, pair them with the NCERT Solutions linked on this page so you can write out complete answers and practise the algebra and quadratic sums step by step.