在三角形ABC中,角A,B,C的对边分别为a,b,c,已知4sin^2(A+B)/2-cos2C=7/2,且a+b=5,c=根号7.(1)求角C的大小?(2)求三角形ABC的面积?最好呢详细一点,特别公式变形的过程
来源:学生作业帮助网 编辑:作业帮 时间:2024/08/30 19:01:40
![在三角形ABC中,角A,B,C的对边分别为a,b,c,已知4sin^2(A+B)/2-cos2C=7/2,且a+b=5,c=根号7.(1)求角C的大小?(2)求三角形ABC的面积?最好呢详细一点,特别公式变形的过程](/uploads/image/z/563541-69-1.jpg?t=%E5%9C%A8%E4%B8%89%E8%A7%92%E5%BD%A2ABC%E4%B8%AD%2C%E8%A7%92A%2CB%2CC%E7%9A%84%E5%AF%B9%E8%BE%B9%E5%88%86%E5%88%AB%E4%B8%BAa%2Cb%2Cc%2C%E5%B7%B2%E7%9F%A54sin%5E2%EF%BC%88A%2BB%EF%BC%89%2F2-cos2C%3D7%2F2%2C%E4%B8%94a%2Bb%3D5%2Cc%3D%E6%A0%B9%E5%8F%B77.%EF%BC%881%EF%BC%89%E6%B1%82%E8%A7%92C%E7%9A%84%E5%A4%A7%E5%B0%8F%3F%EF%BC%882%EF%BC%89%E6%B1%82%E4%B8%89%E8%A7%92%E5%BD%A2ABC%E7%9A%84%E9%9D%A2%E7%A7%AF%3F%E6%9C%80%E5%A5%BD%E5%91%A2%E8%AF%A6%E7%BB%86%E4%B8%80%E7%82%B9%2C%E7%89%B9%E5%88%AB%E5%85%AC%E5%BC%8F%E5%8F%98%E5%BD%A2%E7%9A%84%E8%BF%87%E7%A8%8B)
xRN@N0lZg +7H4DDb!j#!H@忘^ﴄ/8̹sG.E;jJ0hFt5iI=wIQ빕yMBԠ)F.WIAY\'J[(H`6fQf4?YsLVv T0G2ֿgN%n
E]L
= =&SN5AP>Yc
&RDXEv4oٛI88ŶөA\R$qN7ov/+F*'j'`ڕE+&