http://weewee.sgforums.com/forums/2297/topics/329836 en-US 60 <p>cot 2x = cos 2x * cosec 2x</p> <p>hence, 8 cosec 2x cos 2x cosec 2x = 3</p> <p>8 cos 2x = 3 (sin 2x )^2<br /> 8 cos 2x = 3 - 3 (cos 2x )^2<br /> 3 (cos 2x )^2 + 8 cos 2x - 3 = 0<br /> (3 cos 2x -1) (cos 2x + 3) = 0<br /> cos 2x = 1/3&nbsp; or&nbsp; cos 2x = -3 (reject because cos is between -1 and 1)</p> <p>0 deg &lt; x &lt; 180 deg<br /> 0 deg &lt; 2x &lt; 360 deg</p> <p>so 2x = 70.53, 298.47<br /> x = 35.3 deg, 144.7 deg</p> <p>Regards,<br /> Eagle (<a href="http://www.freewebs.com/strategictuition" rel= "nofollow">Strategic Tuition</a>)</p> Sun, 07 Sep 2008 19:04:30 +0800 weewee.sgforums.com:2297:329836:8380170 eagle http://weewee.sgforums.com/forums/2297/topics/329836 <p>Need help with this question. Here goes:</p> <p>&nbsp;</p> <p>Find the values of x, where 0 deg &lt; x &lt; 180 deg, such that</p> <p>8 cosec 2x cot 2x = 3</p> <p>&nbsp;</p> <p>Thanks guys!</p> Sun, 07 Sep 2008 18:39:13 +0800 weewee.sgforums.com:2297:329836:8380098 bonkysleuth http://weewee.sgforums.com/forums/2297/topics/329836