### WHY sin x AND cosec x ARE POSITIVE IN SECOND QUADRANT?

जब भी मै बच्चो से पूछता हूँ कि sin x and cosec x, IInd quadrant में positive क्यों होता है? cos x and sec x, IVth में और tan x and cot x IIIrd में? हमेशा answer आता हैं, Sir, ALL SCHOOL TO COLLEGE OR ADD SUGAR TO COFFEE, etc. कुछ ही बच्चों को इसका […]

### TRIGONOMETRY FORMULAE

Trigonometry Formulae: Don’t try to remember just know the concept of derivation With the help of sin (A + B), we can derive all the remaining trigonometric formulae. Let’s see, how ….. Compound Angle (1) \(\sin \left( A+B \right)=\sin A\cos B+\cos A\sin B\) (2) \(\sin \left( A-B \right)=\sin A\cos B-\cos A\sin B\) (3) \(\cos \left( […]

### MULTIPLE ANGLE

A multiple angle is an angle which is written as a multiple of single function. Example for multiple angles Multiple angle formulas: 1. 2. 3. Question1 : Solve Solution Consider the equation Use the multiple formulae as follow: Written as follows: Set the factors equal to zero as follows: Therefore, the solution is: […]

### TRIGONOMETRIC RATIOS OF ALLIED ANGLES

Two angles are allied if their sum or difference is a multiple of 90o. If is any angle, then etc are called as allied angles. General trigonometric ratios and allied terms are listed below: Example: The value of trigonometric function is; We know that, , then; Question 1: Find the value of trigonometric function Solution […]

### RELATION BETWEEN DEGREES AND RADIANS

Relation between Degrees and Radians A radian is a measure of an angle, indicating the ratio between the arc length and the radius of a circle, which is expressed as follows: Since, the arc length of a full circle is the same as the circumference of a circle, which is written as, then, the radian […]

### SYSTEM OF MEASUREMENT OF ANGLES

Angle Definition An angle is formed by two rays that with common endpoints, where, ray is the straight line. One ray is called the initial side and other one is called as terminal side. There are two systems used for the measurement of angles in trigonometry. 1. Sexagesimal System 2. Circular System 1. Sexagesimal System […]