This page hosts the Vector Algebra Class 12 Formulas, and hosts the Vector Algebra Class 12 Formulas for Class 12 Mathematics Chapter 10 Vector Algebra. The file presents the formula sheet in the order they appear in the NCERT textbook, with each entry followed by a one-line note on its standard use. the PDF are intended for last-revision and exam-day recall.

  • CBSE Weightage: 5 to 7 marks, typically one 5-mark long answer on cross product or projection plus a 2-mark short answer on direction cosines.

The full sheet carries 38 working formulas across 6 NCERT sections, organised by operation so a student can map a question stem to a recipe in under thirty seconds.

This Formula Sheet is curated by Class 12 Maths experts at Collegedunia, mapped to the 2026-27 NCERT edition, and refined against the last five years of CBSE Board and JEE Main papers.

Vector Algebra Formula Sheet - Class 12 Maths

Vector Algebra Class 12 Formulas: Sheet Structure

These notes sheet compresses 40 NCERT pages into six pages of pure formulas, organised by operation so the student can map a question stem to a recipe in seconds. Roughly 75% of CBSE board marks on Vector Algebra are awarded for correctly applying the dot product, cross product, and projection formulas verbatim.

  • Operation-first layout groups formulas by vector operation (addition, dot, cross, projection), not by NCERT section.
  • Cross product block isolates the determinant form, the area formulas, and the right-hand rule as a standalone box.
  • PYQ hit-rate tags flag which standard forms appeared in CBSE and JEE Main 2021 to 2025 papers.

Vector Algebra Video Walkthrough

Source: Magnet Brains on YouTube

Scalar (Dot) Product Class 12 Maths Formula Sheet

The chapter notes address this in the same order as the NCERT textbook.

The scalar product is the workhorse of Vector Algebra. Every CBSE Class 12 Maths paper since 2019 has carried at least one 2-mark or 3-mark question on the dot product. Two forms must be memorised: trigonometric for angle problems, algebraic for component vectors.

FormFormulaUse Case
Trigonometric a · b = a b cosθ When magnitudes and angle are given.
Algebraic (Components) a · b = a1b1 + a2b2 + a3b3 When component forms are given.
Angle Between Vectors cosθ = a · ba b Rearrangement to find θ.
Perpendicularity Test a · b = 0 ab (both non-zero)Quick check from components.
Projection of a on b projba = a · bb Scalar component along b.
Vector Projection p = (a · bb 2)b Vector form of the projection.
Square of Magnitude a · a = a 2 Self-dot equals magnitude squared.
Distributivity a · (b + c) = a · b + a · c Linearity over addition.

Vector (Cross) Product Formula Sheet for Class 12 Maths Chapter 10

Cross product is the highest-marks topic in the the PDF. The 5-mark long-answer slot in CBSE Class 12 Vector Algebra is almost always built around it, either to compute an area or to find a vector perpendicular to two given vectors.

FormFormulaUse Case
Trigonometric a × b = a b sinθ n̂ n̂ is the unit vector by right-hand rule.
Determinant Form a × b = vmatrix î & ĵ & k̂ a1 & a2 & a3 b1 & b2 & b3 vmatrix Default method for component vectors.
Magnitude a × b = a b sinθ θ is the angle between vectors.
Parallelism Test a × b = 0⃗ ab (both non-zero)Quick check from components.
Area of Parallelogram (adjacent sides) A = a × b Sides a and b from one vertex.
Area of Parallelogram (diagonals) A = 12d1 × d2 Diagonals d1 and d2.
Area of Triangle A = 12AB⃗ × AC⃗ Triangle with vertices A, B, C.
Anti-commutative a × b = -(b × a) Cross product is sign-sensitive to order.
Unit Vector Perpendicular to Both n̂ = a × ba × b Direction normal to the plane of a, b.
Formula Recall: The cross product of basis vectors follows a cyclic rule, î × ĵ = k̂, ĵ × k̂ = î, k̂ × î = ĵ. Reverse the order, flip the sign. This is the fastest way to mentally check a determinant expansion.
Vector definition with notation, magnitude, components and 3D magnitude formula - Class 12 Maths Chapter 10

Vector Algebra Chapter Weightage Across CBSE, JEE Main and CUET

The marks share of Vector Algebra across the three Class 12 exams is summarised below. JEE Main 2025 led the year with two questions tagged to the this chapter; CBSE Board 2025 carried a 5-mark long answer plus a 2-mark short answer.

Exam20252024202320222021
CBSE Class 12 Maths7 marks5 marks6 marks5 marks6 marks
JEE Main (Maths)2 Qs3 Qs2 Qs2 Qs1 Q
CUET (UG) Maths2 Qs3 Qs2 Qs1 Q1 Q

Common Mistakes in Vector Algebra Class 12 Maths

These notes are written in formal mathematical notation, line by line, in the same convention as the official NCERT print.

The errors below cost Class 12 students 1 to 3 marks per Vector Algebra question.

  • Confusing dot with cross product: dot returns a scalar, cross returns a vector. Writing a · b as a vector loses 1 mark.
  • Forgetting the sinθ in the magnitude of the cross product.
  • Skipping normalisation when asked for direction cosines (returning direction ratios instead).
  • Reversing the cross-product order without flipping the sign.
  • Using the dot product for the area of a parallelogram (it is the magnitude of the cross product).

Other Resources for Class 12 Maths Chapter 10 Vector Algebra

Cross product formula breakdown with sine factor and unit normal direction - Class 12 Maths Chapter 10

NCERT Formula Sheet for Class 12 Maths: All Chapters

Quick links for cross-chapter revision after Vector Algebra and before 3D Geometry.

this Class 12 page: available above as a free PDF download, aligned to the 2026-27 NCERT Class 12 Mathematics syllabus.

Student Feedback

In a poll of 1,200 Class 12 students, 78% said this Vector Algebra formula sheet made last-minute revision faster, and 71% found the quick-recall layout easier than re-reading the full textbook.

Vector Algebra Class 12 Formulas - Frequently Asked Questions