Class 11 Maths - CBSE
Trigonometric Functions
The Trigonometric Functions chapter in Class 11 CBSE Mathematics expands the study of trigonometry from right-angled triangles to general angles measured in radians and degrees. Students learn about the unit circle, domain and range of six trigonometric functions, and how their signs vary across four quadrants. The chapter introduces vital algebraic identities including sum, difference, product, and multiple-angle formulas, alongside the general solutions of trigonometric equations. This fundamental topic is crucial for board exams, laying the groundwork for calculus, complex numbers, and physics problems in higher classes, consistently featuring in both short and long answer questions.
Start Learning FreeKey Concepts
Angle Measurement in Radians and Degrees
Angles can be measured in degrees or radians, where 180 degrees equals pi radians, serving as the standard unit for calculus.
Trigonometric Functions and Unit Circle
Trigonometric functions are defined using the coordinates of points on a unit circle, allowing values for any real number angle.
Signs of Trigonometric Functions
The signs of sin, cos, tan, and their reciprocals vary across the four quadrants based on the coordinates (All Silver Tea Cups rule).
Compound Angle Identities
Formulas for trigonometric functions of sum and difference of angles, such as sin(x + y) and cos(x + y), used to simplify complex expressions.
Trigonometric Equations
Equations involving trigonometric functions that have principal and general solutions valid for all integer values of n.
Important Formulas
Board Exam Info
In the CBSE Class 11 Mathematics examination, Trigonometric Functions along with Inverse Trigonometric Functions (or general trigonometry) typically carries around 6 to 8 marks. Common question types include proving identities, converting degrees to radians, finding the general solutions of trigonometric equations, and evaluating values using compound angle formulas.
Frequently Asked Questions
What is the difference between a degree and a radian?
A degree is 1/360th of a full rotation, whereas a radian is the angle subtended at the center of a circle by an arc equal in length to its radius.
How do I remember the signs of trigonometric functions in different quadrants?
Use the mnemonic 'All Silver Tea Cups' (or 'Add Sugar To Coffee'), which stands for All positive in 1st, Sine in 2nd, Tan in 3rd, and Cosine in 4th quadrant.
What is the difference between principal solutions and general solutions?
Principal solutions lie within the interval [0, 2pi], while general solutions express all possible values of an angle satisfying an equation using an integer variable n.
Learn Trigonometric Functions with Your AI Tutor
10 different ways to study this chapter. Free for 3 chapters per day.
Lecture
Key Points
Interactive
Quiz
Flashcards