trigonometry xi important question

\ 180 o = p radian = 180 o 1 radian = 57.2958 o (approximately) = 57 o 17' 44.81" (approximately) = 206265 seconds (approximately) = 0.01745 radi..

From the above observation, we find (i) sin A = cos B where A + B = 90 o \ Sine of an angle = Cosine of its complement sin A = cos (90 - A) o sin 40 o = cos (90 - 40) o = cos 50 o (ii) = tan A (iii) By Pythagoras theorem a 2 + b 2 = c 2 \ sin 2 A + cos 2 A = 1 These..

Trigonometry - is that branch of mathematics which deals with the measurement of sides and angles of triangles. The word, trigonometry is derived from Greek, which means the measure of triangles. This subject was originally developed to solve problems in astronomy and geometry. ..

An angle is an amount of rotation of a half-line (or ray) in a plane about its end point from an initial position to a terminal position. The important terms are: Measurement of angle, Positive and Negative angles, Lines at right angles, Quadrants, Angle in standard positio..

When calculating sides or angles of right angled triangles, it is easiest to use the appropriate trigonometric relation. Finding the value of trigonometric ratios from the tables is learnt easily. Nowadays of course calculators are able to give accurate values for any degree of tan, sin..

In the above topics many identities have been discussed. They are true for all values of the angles for which trigonometric functions are defined. In this section we prove identities, where a certain relationship exists among the angles considered. Many interesting and important..

Introduction - When calculating sides or angles of right angled triangles, it is easiest to use the appropriate trigonometric relation. Finding the value of trigonometric ratios from the tables is learnt easily. Nowadays of course calculators are able to give accurate values for any degree of tan, ..

Conditional Trigonometric Identities - In the previous sections many identities have been discussed. They are true for all values of the angles for which trigonometric functions are defined. In this section we prove identities, where a certain relationship exists among the angles considered. Many i..

Trigonometry - With trigonometry we can find the height of a building or the width of a river without actually climbing or crossing. Certain basic definitions are necessary to further develop this subject. The ratios of two sides of a triangle are taken. There are six possible c..

(i) Sin q means a particular ratio. It is not sin multiplied by q . (ii) For trigonometrical ratios, short form T-ratios will be used. (iii) In right angled triangles T-ratios are obtained only for acute angles. (iv) T-ratios depend on only the magnitude of the angles and..