Lesson#2 <br />Important Formulae based on the concept of Allied angles: <br />Important Points about the use of the concept of Allied angles <br />If θ is added to or subtracted from odd multiple of right angle, the trigonometric ratios change into co−ratios. <br />If θ is added to or subtracted from an even multiple of right angle, the trigonometric ratios shall remain same. <br />Sign of the result is determined by the original trigonometric ratio by the use of the quadrant in which angle lies. <br />Example: csc(1003 /2+)=sec <br />Trigonometric Identities <br />Chapter No 10 <br />Exercise No 10.1 <br />Mathematics <br />part 1
