NCERT Solutions for Class 10 Maths Chapter 8 Introduction to Trigonometry
NCERT Solutions for Class 10 Maths Chapter 8 Introduction to Trigonometry covers trigonometric ratios of an acute angle, trigonometric ratios of specific angles (0°, 30°, 45°, 60°, 90°), and trigonometric identities.
Overview of Topics & Subtopics (Click to Jump)
1. Trigonometric Ratios
Short Note:
• For a right triangle with an acute angle θ: sinθ = opposite/hypotenuse, cosθ = adjacent/hypotenuse, tanθ = opposite/adjacent, and their reciprocals cosecθ, secθ, cotθ.
• tanθ = sinθ/cosθ and cotθ = cosθ/sinθ.
2. Trigonometric Ratios of Specific Angles
Short Note:
• sin: 0°=0, 30°=1/2, 45°=1/√2, 60°=√3/2, 90°=1.
• cos: 0°=1, 30°=√3/2, 45°=1/√2, 60°=1/2, 90°=0.
• tan: 0°=0, 30°=1/√3, 45°=1, 60°=√3, 90°=undefined.
3. Trigonometric Ratios of Complementary Angles
Short Note:
• sin(90°−θ) = cosθ; cos(90°−θ) = sinθ; tan(90°−θ) = cotθ; cot(90°−θ) = tanθ; sec(90°−θ) = cosecθ; cosec(90°−θ) = secθ.
4. Trigonometric Identities
Short Note:
• sin²θ + cos²θ = 1
• 1 + tan²θ = sec²θ
• 1 + cot²θ = cosec²θ
NCERT Textbook Exercise Questions
Read More & Chapter Resources
These short notes are designed for quick revision. Read the main points once, then use the related material below to practise the same chapter. Revising a concept and checking it with questions can make your preparation more focused.