{"id":9401,"date":"2022-01-12T02:12:54","date_gmt":"2022-01-11T20:42:54","guid":{"rendered":"https:\/\/mathemerize.com\/?p=9401"},"modified":"2022-01-12T02:20:33","modified_gmt":"2022-01-11T20:50:33","slug":"what-is-the-value-of-cos-18-degrees","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/what-is-the-value-of-cos-18-degrees\/","title":{"rendered":"What is the Value of Cos 18 Degrees ?"},"content":{"rendered":"

Solution :<\/h2>\n

The value of cos 18 degrees<\/strong> is \\(\\sqrt{10 + 2\\sqrt{5}}\\over 4\\)<\/strong>.<\/p>\n

Proof :<\/strong><\/p>\n

We know that the value of sin 18 degrees<\/a> is \\(\\sqrt{5} – 1\\over 4\\).<\/p>\n

Putting \\(\\theta\\) = 18 in\u00a0 \\(cos \\theta\\) = \\(\\sqrt{1 – sin^2 \\theta}\\), we get<\/p>\n

cos 18 = \\(\\sqrt{1 – sin^2 18}\\) = \\(\\sqrt{1 – ({\\sqrt{5} – 1\\over 4})^2}\\) = \\(\\sqrt{10 + 2\\sqrt{5}}\\over 4\\)<\/p>\n

Hence, cos 18 degrees is \\(\\sqrt{10 + 2\\sqrt{5}}\\over 4\\).<\/p>\n","protected":false},"excerpt":{"rendered":"

Solution : The value of cos 18 degrees is \\(\\sqrt{10 + 2\\sqrt{5}}\\over 4\\). Proof : We know that the value of sin 18 degrees is \\(\\sqrt{5} – 1\\over 4\\). Putting \\(\\theta\\) = 18 in\u00a0 \\(cos \\theta\\) = \\(\\sqrt{1 – sin^2 \\theta}\\), we get cos 18 = \\(\\sqrt{1 – sin^2 18}\\) = \\(\\sqrt{1 – ({\\sqrt{5} – …<\/p>\n

What is the Value of Cos 18 Degrees ?<\/span> Read More »<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"default","ast-global-header-display":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":""},"categories":[43,60],"tags":[],"yoast_head":"\nWhat is the Value of Cos 18 Degrees ? - Mathemerize<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/mathemerize.com\/what-is-the-value-of-cos-18-degrees\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"What is the Value of Cos 18 Degrees ? - Mathemerize\" \/>\n<meta property=\"og:description\" content=\"Solution : The value of cos 18 degrees is (sqrt{10 + 2sqrt{5}}over 4). Proof : We know that the value of sin 18 degrees is (sqrt{5} – 1over 4). Putting (theta) = 18 in\u00a0 (cos theta) = (sqrt{1 – sin^2 theta}), we get cos 18 = (sqrt{1 – sin^2 18}) = (sqrt{1 – ({sqrt{5} – … What is the Value of Cos 18 Degrees ? 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