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☆算术计算1题
〖1/1算式〗
作业:求算式 4*(cos(2*π/7))^2*4*(cos(4*π/7))^2*4*(cos(8*π/7))^2 的值.
题型:数学计算
解:
4*(cos(2*π/7))^2*4*(cos(4*π/7))^2*4*(cos(8*π/7))^2
=4*(cos0.897598)^2*4*(cos(4*π/7))^2*4*(cos(8*π/7))^2
=4*0.62349^2*4*(cos(4*π/7))^2*4*(cos(8*π/7))^2
=4*0.62349^2*4*(cos1.795196)^2*4*(cos(8*π/7))^2
=4*0.62349^2*4*(-0.222521)^2*4*(cos(8*π/7))^2
=4*0.62349^2*4*(-0.222521)^2*4*(cos3.590392)^2
=4*0.62349^2*4*(-0.222521)^2*4*(-0.900969)^2
=4*0.3887397801*4*(-0.222521)^2*4*(-0.900969)^2
=4*0.3887397801*4*0.049515595441*4*(-0.900969)^2
=4*0.3887397801*4*0.049515595441*4*0.811745138961
=1.554959*4*0.049515595441*4*0.811745138961
=6.219836*0.049515595441*4*0.811745138961
=0.307979*4*0.811745138961
=1.231916*0.811745138961
=1.000002 答案:4*(cos(2*π/7))^2*4*(cos(4*π/7))^2*4*(cos(8*π/7))^2=1.000002 注:弧度制你的问题在这里没有得到解决?请到 热门难题 里面看看吧!