Mon July 30, 2012 By:
sec37/cosec 53 + 2(cot15 cot25 cot 45 cot75 cot65) -3(sin SQUARE 18 + sin SQUARE 72)


Expert Reply
Mon July 30, 2012
In such type of questions, it is mentioned that "solve without using trigonometric tables".
This basically means that we should not make use of trigonometric tables.
However, we can always use the trigonometric values of the standard angles (0, 30, 45, 60, 90 degrees).
We get these values by a proper proof which may or may not be possible for all the angles. So, we can make use of the standard values of trigonometric ratios.
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