在RT△ABC中,角C=90,角A,角B的对边分别为a,b,c,由sinA=a/c,cosA=b/c可得sin²A+cos²A=a²/c²+b²/c²=(a²+b²)/c²=1根据以上研究,求sin²13度+sin²23度+sin²41度+cos²13度+cos&s
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![在RT△ABC中,角C=90,角A,角B的对边分别为a,b,c,由sinA=a/c,cosA=b/c可得sin²A+cos²A=a²/c²+b²/c²=(a²+b²)/c²=1根据以上研究,求sin²13度+sin²23度+sin²41度+cos²13度+cos&s](/uploads/image/z/3842094-30-4.jpg?t=%E5%9C%A8RT%E2%96%B3ABC%E4%B8%AD%2C%E8%A7%92C%3D90%2C%E8%A7%92A%2C%E8%A7%92B%E7%9A%84%E5%AF%B9%E8%BE%B9%E5%88%86%E5%88%AB%E4%B8%BAa%2Cb%2Cc%2C%E7%94%B1sinA%3Da%2Fc%2CcosA%3Db%2Fc%E5%8F%AF%E5%BE%97sin%26sup2%3BA%2Bcos%26sup2%3BA%3Da%26sup2%3B%2Fc%26sup2%3B%2Bb%26sup2%3B%2Fc%26sup2%3B%3D%28a%26sup2%3B%2Bb%26sup2%3B%29%2Fc%26sup2%3B%3D1%E6%A0%B9%E6%8D%AE%E4%BB%A5%E4%B8%8A%E7%A0%94%E7%A9%B6%2C%E6%B1%82sin%26sup2%3B13%E5%BA%A6%2Bsin%26sup2%3B23%E5%BA%A6%2Bsin%26sup2%3B41%E5%BA%A6%2Bcos%26sup2%3B13%E5%BA%A6%2Bcos%26s)
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