{"id":7213,"date":"2021-10-23T02:07:37","date_gmt":"2021-10-22T20:37:37","guid":{"rendered":"https:\/\/mathemerize.com\/?p=7213"},"modified":"2021-10-25T09:59:18","modified_gmt":"2021-10-25T04:29:18","slug":"find-the-maximum-value-of-1-sinpiover-4-theta-2cospiover-4-theta","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/find-the-maximum-value-of-1-sinpiover-4-theta-2cospiover-4-theta\/","title":{"rendered":"Find the maximum value of 1 + \\(sin({\\pi\\over 4} + \\theta)\\) + \\(2cos({\\pi\\over 4} – \\theta)\\)"},"content":{"rendered":"
We have 1 + \\(sin({\\pi\\over 4} + \\theta)\\) + \\(2cos({\\pi\\over 4} – \\theta)\\)<\/p>\n
= 1 + \\(1\\over sqrt{2}\\)\\((cos\\theta + cos\\theta)\\) + \\(\\sqrt{2}\\)\\((cos\\theta + cos\\theta)\\)<\/p>\n
= 1 + \\(({1\\over \\sqrt{2}} + \\sqrt{2})\\) + \\((cos\\theta + cos\\theta)\\)<\/p>\n
= 1 + \\(({1\\over \\sqrt{2}} + \\sqrt{2})\\).\\(\\sqrt{2}cos(\\theta – {pi\\over 4})\\)<\/p>\n
\\(\\therefore\\)\u00a0 \u00a0Maximum Value = 1 + \\(({1\\over \\sqrt{2}} + \\sqrt{2})\\).\\(\\sqrt{2}\\) = 4<\/p>\n
Evaluate sin78 \u2013 sin66 \u2013 sin42 + sin6.<\/a><\/p>\n If A + B + C = \\(3\\pi\\over 2\\), then cos2A + cos2B + cos2C is equal to<\/a><\/p>\n \\(sin5x + sin2x \u2013 sinx\\over {cos5x + 2cos3x + 2cos^x + cosx}\\) is equal to<\/a><\/p>\n