Trigonometry (Ratios, Identities, Equations) for JEE

• sin²x + cos²x = 1 is the base identity
• Use ASTC to find signs by quadrant
• General solution of sin x = sin α: x = nπ + (−1)ⁿα
• Sum-to-product formulas simplify sums of sines

• sin(A ± B) = sinA cosB ± cosA sinB
• cos2A = 1 − 2sin²A = 2cos²A − 1
• tan(A + B) = (tanA + tanB)/(1 − tanA tanB)
• cos x = cos α → x = 2nπ ± α

Printable Trigonometry (Ratios, Identities, Equations) formula sheet: formulas, key ideas and traps on one page. Save it as a PDF for offline revision.

• Losing solutions when dividing by a trig function
• Wrong general solution form
• Domain restrictions on tan and sec

Appears frequently. Trigonometry is used everywhere in calculus and conics. Keep identities fresh.

Chapter names follow the current rationalised NCERT textbooks. Read these sections before solving PYQs.

Question. If sin(x) + sin(y) = a and cos(x) + cos(y) = b, find the value of tan((x+y)/2) in terms of a and b.

This example was solved twice independently and both solutions agree.

Full-chapter free lectures picked from YouTube search results by views, from established JEE channels (mostly in Hinglish). Use the subtopic list to jump straight to the part you need (timestamps come from each video's own chapter list). Watch one, then solve PYQs the same day.

• Trigonometric Ratio & Identities FULL CHAPTER | Class 11th Maths | Arjuna JEE — Arjuna JEE, 4:40:34
  Jump to a subtopic (21)

  • 00:00 Introduction
  • 10:40 Radian Measure
  • 23:18 Sign Convention
  • 29:47 Negative Angle Formulas
  • 32:19 ASTC Rule
  • 43:58 Allied Angles
  • 56:58 Table
  • 01:14:35 Compound Angles
  • 01:31:01 Double Angles
  • 01:59:53 Triple Angles
  • 02:03:15 Multiple Angles
  • 02:05:40 Sub-Multiple Angles
  • 02:20:14 Factorization & Defactorization Formulas
  • 02:33:09 Graphs of Trigonometric Functions
  • 02:49:37 Extra Formulas
  • 03:07:02 Extra Formulas-2
  • 03:33:01 Extra Formulas-3
  • 03:34:46 Extra Formulas-4
  • 04:02:09 Range of Trigonometric Functions
  • 04:16:52 PYQs
  • 04:38:22 Thank You Bachoo
• TRIGONOMETRIC FUNCTIONS in One Shot: All Concepts & PYQs Covered || JEE Main & Advanced — JEE Wallah, 6:29:16
  Jump to a subtopic (21)

  • 00:00 Introduction
  • 10:30 Topics
  • 17:00 Class 10th Formulas
  • 48:40 Radian measure
  • 57:45 Area of sector
  • 1:00:30 Sign convention
  • 1:09:24 ASTC rule
  • 1:24:30 Negative angle formulas
  • 1:39:40 Trigonometric table
  • 2:02:01 Graphs
  • 2:24:24 Compound angles
  • 2:31:38 Important values
  • 2:55:30 Double angles
  • 3:38:00 Triple angles
  • 3:48:30 Multiple angles
  • 4:04:20 4 important formula
  • 4:18:00 Factorization and de-factorization formula
  • 4:45:20 Extra formulas
  • 5:49:10 Range of Trigonometric functions
  • 6:04:00 Questions
  • 6:24:57 Thank You Bachhon!

• 9 JEE Main 2026 PYQs on Trigonometry (Ratios, Identities, Equations), with solutions.
• Read the chapter in NCERT textbooks (official, free), then solve its NCERT Exemplar (official, free) questions.
• Chapter-wise past questions: JEE Main and Advanced PYQs and question bank.
• Timed practice tests: NTA Abhyas practice tests (official, free) and our free mock tests.
• See it move: interactive simulation.