In this article, we shall study to find the value of trigonometric expressions involving standard angles. Trigonometric functions values of some standard angles are given below: Evaluate the following: Example 01: sin20c + sin2(π/6)c + sin2(π/3)c + sin2(π/2)c = (0)2 + (1/2)2 + (√3/2)2 + (1)2 = 0 + 1/4 + 3/4 + 1 […]
Category: Trigonometry
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Signs of Trigonometric Ratios
In this article, we shall study to find signs of trigonometric ratios (Functions) in different quadrants formed due to co-ordinate axes. Signs of Trigonometric Ratios in Different Quadrants: θ lies in Quadrant → I II III IV Trigonometric Functions↓ sin θ + ve + ve – ve – ve cos θ + ve – ve […]
In this article, we shall find values of trigonometric ratios of standard angles in the third and the fourth quadrants using a standard unit circle. Trigonometric Ratios of 210o or (7π/6)c: Let us consider a standard unit circle Let m∠ AOP = θ = 210o = (7π/6)c m∠ POM = 30o Ray OA is the initial […]
In this article, we shall find values of trigonometric ratios of standard angles in the first and the second quadrants using a standard unit circle. A circle with the centre at the origin and radius 1 is a standard unit circle. Let P(x, y) be any point on the unit circle with m∠ XOP = […]
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Area of Sector
Science > Mathematics > Trigonometry > Angle Measurement > Area of Sector In this article, we shall study to solve problems based on the area of the sector. Example – 01: Find the area of a sector of the circle which subtends an angle of 120° at the centre, if the radius of the circle […]
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Length of an Arc
Science > Mathematics > Trigonometry > Angle Measurement > Length of an Arc In this article, we shall solve problems based on the length of an arc (arc length). Example – 01: Find the length of the arc of a circle of diameter 10 cm, if the arc is subtending an angle of 36° at […]
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Angle Measurement
Science > Mathematics > Trigonometry > Angle Measurement > Angle Measurement In this article, we shall study the problems based on the interior angles of a polygon, and the angle between the hour hand and a minute hand of a clock. Example – 01: If xc = 405° and y° = – (π/12)c. Find x […]
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Measurement of Angle in Radians
Science > Mathematics > Trigonometry > Angle Measurement > Measurement of Angle in Radians In this article, we shall study to find a measure of an angle in radians and degrees. Express following angles in degrees, minutes, and seconds Degrees x 60 = Minutes Minutes x 60 = Seconds 74.87° 74.87° = 74° + 0.87° […]