{"id":11969,"date":"2022-09-08T02:16:21","date_gmt":"2022-09-07T20:46:21","guid":{"rendered":"https:\/\/mathemerize.com\/?p=11969"},"modified":"2022-09-08T02:17:10","modified_gmt":"2022-09-07T20:47:10","slug":"choose-the-correct-option-justify-your-choice","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/choose-the-correct-option-justify-your-choice\/","title":{"rendered":"Choose the correct option. Justify your choice :"},"content":{"rendered":"
Choose the correct option. Justify your choice :<\/p>\n
(i)<\/strong>\u00a0 \\(9 sec^2 A – 9 tan^2 A\\) =<\/p>\n (a)\u00a0 1<\/p>\n (b)\u00a0 9<\/p>\n (c)\u00a0 8<\/p>\n (d)\u00a0 0<\/p>\n (ii)<\/strong>\u00a0 \\((1 – tan \\theta + sec \\theta)\\)\\((1 + cot \\theta – cosec \\theta)\\) =<\/p>\n (a)\u00a0 0<\/p>\n (b)\u00a0 1<\/p>\n (c)\u00a0 2<\/p>\n (d) -1<\/p>\n (iii)<\/strong>\u00a0 (sec A + tan A)(1 – sin A) =<\/p>\n (a)\u00a0 sec A<\/p>\n (b)\u00a0 sin A<\/p>\n (c)\u00a0 cosec A<\/p>\n (c)\u00a0 cos A<\/p>\n (iv)<\/strong>\u00a0 \\(1 + tan^2 A\\over 1 + cot^2 A\\) =<\/p>\n (a)\u00a0 \\(sec^2 A\\)<\/p>\n (b)\u00a0 -1<\/p>\n (c)\u00a0 \\(cot^2 A\\)<\/p>\n (d)\u00a0 \\(tan^2 A\\)<\/p>\n (i)\u00a0 (b)\u00a0\u00a0<\/strong>Because : \\(9 sec^2 A – 9 tan^2 A\\) = 9(\\(9 sec^2 A – 9 tan^2 A\\)) =\u00a0 9(1) = 9<\/strong><\/p>\n (ii)\u00a0 (c)<\/strong>\u00a0 Because : \\((1 – tan \\theta\\) + sec \\theta)\\)\\((1 + cot \\theta – cosec \\theta)\\)<\/p>\n = (1 + \\(sin\\theta\\over cos\\theta\\) + \\(1\\over cos\\theta\\))(1 + \\(cos\\theta\\over sin\\theta\\) – \\(1\\over sin\\theta\\))<\/p>\n = \\(({cos\\theta +sin\\theta})^2 – 1\\over cos\\theta sin\\theta \\)<\/p>\n = \\(1 + 2cos\\theta sin\\theta – 1\\over sin\\theta cos\\theta\\) = \\(2sin\\theta cos\\theta\\over sin\\theta cos\\theta\\) = 2<\/strong><\/p>\n (iii)\u00a0 (d)<\/strong>\u00a0 Because<\/p>\n (sec A + tan A)(1 – sin A) = (\\(1\\over cos A\\) + \\(sin A\\over cos A\\))(1 – sin A) = (\\(1 + sin A\\over cos A\\))(1 – sin A)<\/p>\n = \\(1 – sin^2A\\over cos A\\) = \\(cos^2 A\\over cos A\\) = cos A<\/strong><\/p>\n (iv)\u00a0 (d)<\/strong>\u00a0 Because<\/p>\n \\(1 + tan^2 A\\over 1 + cot^2 A\\) = \\(1 + tan^2 A\\over 1 + {1\\over tan^2 A}\\) = (\\(1 + tan^2 A\\)) \\(\\times\\) \\(tan^2 A\\over 1 + tan^2 A\\) = \\(tan^2 A\\)<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":" Question : Choose the correct option. Justify your choice : (i)\u00a0 \\(9 sec^2 A – 9 tan^2 A\\) = (a)\u00a0 1 (b)\u00a0 9 (c)\u00a0 8 (d)\u00a0 0 (ii)\u00a0 \\((1 – tan \\theta + sec \\theta)\\)\\((1 + cot \\theta – cosec \\theta)\\) = (a)\u00a0 0 (b)\u00a0 1 (c)\u00a0 2 (d) -1 (iii)\u00a0 (sec A + tan …<\/p>\nSolution :<\/h2>\n