\n\n \u03b8<\/strong><\/p>\n<\/td>\n0\u00b0<\/strong><\/td>\n30\u00b0<\/strong><\/td>\n45\u00b0<\/strong><\/td>\n60\u00b0<\/strong><\/td>\n90\u00b0<\/strong><\/td>\n<\/tr>\n\n\n Sin<\/strong><\/p>\n<\/td>\n0<\/td>\n | 1\/2<\/td>\n | 1\/\u221a2<\/td>\n | \u00a0\u221a3\/2<\/td>\n | \n 1<\/p>\n<\/td>\n<\/tr>\n | \n\n Cos<\/strong><\/p>\n<\/td>\n1<\/td>\n | \u00a0\u221a3\/2<\/td>\n | \u00a01\/\u221a2<\/td>\n | 1\/2<\/td>\n | 0<\/td>\n<\/tr>\n | \n\n Tan<\/strong><\/p>\n<\/td>\n0<\/td>\n | \u00a01\/\u221a3<\/td>\n | 1<\/td>\n | \u221a3<\/td>\n | \u221e<\/td>\n<\/tr>\n | \nCosec<\/strong><\/td>\n\u221e<\/td>\n | 2<\/td>\n | \u221a2<\/td>\n | 2\/\u221a3<\/td>\n | \n 1<\/p>\n<\/td>\n<\/tr>\n | \nSec<\/strong><\/td>\n1<\/td>\n | 2\/\u221a3<\/td>\n | \u00a0\u221a2<\/td>\n | 2<\/td>\n | \n \u221e<\/p>\n<\/td>\n<\/tr>\n | \nCot<\/strong><\/td>\n\u221e<\/td>\n | \u221a3<\/td>\n | 1<\/td>\n | 1\/\u221a3<\/td>\n | \n 0<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Trigonometric Ratios Of Some Specific Angles With Examples<\/strong><\/h2>\n<\/p>\n Example 1:<\/strong> \u00a0 \u00a0Evaluate each of the following in the simplest form: \n(i) sin 60\u00ba cos 30\u00ba + cos 60\u00ba sin 30\u00ba \n(ii) sin 60\u00ba cos 45\u00ba + cos 60\u00ba sin 45\u00ba \nSol.\u00a0\u00a0\u00a0\u00a0\u00a0 (i)\u00a0<\/strong>\u00a0sin 60\u00ba cos 30\u00ba + cos 60\u00ba sin 30\u00ba \n\\(=\\frac{\\sqrt{3}}{2}\\times \\frac{\\sqrt{3}}{2}+\\frac{1}{2}\\times \\frac{1}{2}=\\frac{3}{4}+\\frac{1}{4}=1\\) \n(ii)\u00a0<\/strong> sin 60\u00ba cos 45\u00ba + cos 60\u00ba sin 45\u00ba \n\\( =\\frac{\\sqrt{3}}{2}\\times \\frac{1}{\\sqrt{2}}+\\frac{1}{2}\\times \\frac{1}{\\sqrt{2}} \\) \n\\( =\\frac{\\sqrt{3}}{2\\sqrt{2}}+\\frac{1}{2\\sqrt{2}}=\\frac{\\sqrt{3}+1}{2\\sqrt{2}} \\)<\/p>\nExample 2:<\/strong>\u00a0 \u00a0 \u00a0Evaluate the following expression: \n(i) tan 60\u00ba cosec2<\/sup> 45\u00ba + sec2<\/sup> 60\u00ba tan 45\u00ba \n(ii) 4cot2<\/sup> 45\u00ba \u2013 sec2<\/sup> 60\u00ba + sin2<\/sup> 60\u00ba + cos2<\/sup> 90\u00ba. \nSol. \u00a0 \u00a0\u00a0\u00a0(i)<\/strong>\u00a0 tan 60\u00ba cosec2<\/sup> 45\u00ba + sec2<\/sup> 60\u00ba tan 45\u00ba \n= tan 60\u00ba (cosec 45\u00ba)2<\/sup> + (sec 60\u00ba)2<\/sup> tan 45\u00ba \n=\u00a0\u221a3\u00a0\u00d7 (\u221a2)2<\/sup> + (2)2<\/sup>\u00a0\u00d7 1 \n= \u221a3\u00a0\u00a0\u00d7 2 + 4 = 4 + 2\u00a0\u221a3 \n(ii)<\/strong>\u00a0 4cot2<\/sup> 45\u00ba \u2013 sec2<\/sup> 60\u00ba + sin2<\/sup> 60\u00ba + cos2<\/sup> 90\u00ba \n= 4(cot 45\u00ba)2<\/sup> \u2013 (sec 60\u00ba)2<\/sup> + (sin 60\u00ba)2<\/sup> + (cos 90\u00ba)2<\/sup> \n= 4 \u00d7 (1)2<\/sup> \u2013 (2)2<\/sup> + (\u221a3\/2)2\u00a0<\/sup>+ 0 \n= 4 \u2013 4 + 3\/4 + 0 = 3\/4<\/p>\n | | | | | | | | | | | | |