quadratic formula<\/a>,<\/p>\n\\(\\implies\\) \\(sin \\theta\\) = \\(-2 \\pm \\sqrt{4 + 16}\\over 8\\)<\/p>\n
\\(\\implies\\) \\(sin \\theta\\) = \\(-1 \\pm \\sqrt{5}\\over 4\\)<\/p>\n
Since \\(\\theta\\) lies in 1st quadrant \\(\\therefore\\) \\(sin \\theta\\) > 0<\/p>\n
\\(\\implies\\) \\(sin \\theta\\) = \\(-1 + \\sqrt{5}\\over 4\\) = \\(\\sqrt{5} – 1\\over 4\\)<\/p>\n
Hence, sin 18 degrees = \\(\\sqrt{5} – 1\\over 4\\)<\/p>\n","protected":false},"excerpt":{"rendered":"
Solution : The value of sin 18 degrees is \\(\\sqrt{5} – 1\\over 4\\). Proof : Let \\(\\theta\\) = 18 degrees. Then, \\(5\\theta\\) = 90 degrees \\(\\implies\\) \\(2\\theta\\) + \\(3\\theta\\) = 90 \\(\\implies\\) \\(2\\theta\\) = 90 – \\(3\\theta\\) \\(\\implies\\) \\(sin 2\\theta\\) = \\(sin (90 – 3\\theta)\\) \\(\\implies\\) \\(sin 2\\theta\\) = \\(cos 3\\theta\\) By using the formula …<\/p>\n
What is the Value of Sin 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 Sin 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-sin-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 Sin 18 Degrees ? - Mathemerize\" \/>\n<meta property=\"og:description\" content=\"Solution : The value of sin 18 degrees is (sqrt{5} – 1over 4). 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- Mathemerize","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/mathemerize.com\/what-is-the-value-of-sin-18-degrees\/","og_locale":"en_US","og_type":"article","og_title":"What is the Value of Sin 18 Degrees ? - Mathemerize","og_description":"Solution : The value of sin 18 degrees is (sqrt{5} – 1over 4). Proof : Let (theta) = 18 degrees. Then, (5theta) = 90 degrees (implies) (2theta) + (3theta) = 90 (implies) (2theta) = 90 – (3theta) (implies) (sin 2theta) = (sin (90 – 3theta)) (implies) (sin 2theta) = (cos 3theta) By using the formula … What is the Value of Sin 18 Degrees ? 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