{"id":11669,"date":"2022-08-14T01:36:56","date_gmt":"2022-08-13T20:06:56","guid":{"rendered":"https:\/\/mathemerize.com\/?p=11669"},"modified":"2022-08-14T01:37:02","modified_gmt":"2022-08-13T20:07:02","slug":"if-cot-theta-7over-8-evaluate-i-1-sintheta1-sinthetaover-1-costheta1-costheta-ii-cot2-theta","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/if-cot-theta-7over-8-evaluate-i-1-sintheta1-sinthetaover-1-costheta1-costheta-ii-cot2-theta\/","title":{"rendered":"If cot \\(\\theta\\) = \\(7\\over 8\\), evaluate : (i) \\({(1 + sin\\theta)(1 – sin\\theta)}\\over {(1 + cos\\theta)(1 – cos\\theta)}\\) (ii) \\(cot^2 \\theta\\)"},"content":{"rendered":"
(i)<\/strong>\u00a0 In \\(\\triangle\\) ABC,\u00a0 \\(cot \\theta\\) = \\(7\\over 8\\) = \\(AB\\over BC\\)<\/p>\n Let AB = 7k and BC = 8k<\/p>\n Now, AC = \\(\\sqrt{{AB}^2 + {BC}^2}\\) = \\(\\sqrt{113k^2}\\)<\/p>\n So, AC = \\(\\sqrt{113}k\\)<\/p>\n Thus,\u00a0 \\(sin \\theta\\) = \\(8k\\over \\sqrt{113}k\\) = \\(8\\over \\sqrt{113}\\)<\/p>\n \\(cos \\theta\\) = \\(7k\\over \\sqrt{113}k\\) = \\(7\\over \\sqrt{113}\\)<\/p>\n Now,\u00a0 \\({(1 + sin\\theta)(1 – sin\\theta)}\\over {(1 + cos\\theta)(1 – cos\\theta)}\\) = \\(49\\over 64\\)<\/strong><\/p>\n (ii)<\/strong>\u00a0 \\(cot^2 \\theta\\) = \\(({7\\over 8})^2\\) = \\(49\\over 64\\)<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":" Solution : (i)\u00a0 In \\(\\triangle\\) ABC,\u00a0 \\(cot \\theta\\) = \\(7\\over 8\\) = \\(AB\\over BC\\) Let AB = 7k and BC = 8k Now, AC = \\(\\sqrt{{AB}^2 + {BC}^2}\\) = \\(\\sqrt{113k^2}\\) So, AC = \\(\\sqrt{113}k\\) Thus,\u00a0 \\(sin \\theta\\) = \\(8k\\over \\sqrt{113}k\\) = \\(8\\over \\sqrt{113}\\) \\(cos \\theta\\) = \\(7k\\over \\sqrt{113}k\\) = \\(7\\over \\sqrt{113}\\) Now,\u00a0 \\({(1 + sin\\theta)(1 …<\/p>\n