作业帮1.设函数f(x)=π sinX(X属于R)(1)证明f(x+2kπ)-f(x)=2kπsinX(k属于Z)(2)设X.为f(x)的一个极直点,证明[f(x.)]2=x4/(1+X.2)2.在三角形ABC中,∠C=60°a,b,c分别为∠A,∠B,∠C的对边,则a/(b+c)加b/(c+a)的和为?Thank you ...不
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![1.设函数f(x)=π sinX(X属于R)(1)证明f(x+2kπ)-f(x)=2kπsinX(k属于Z)(2)设X.为f(x)的一个极直点,证明[f(x.)]2=x4/(1+X.2)2.在三角形ABC中,∠C=60°a,b,c分别为∠A,∠B,∠C的对边,则a/(b+c)加b/(c+a)的和为?Thank you ...不](/uploads/image/z/10261382-14-2.jpg?t=1.%E8%AE%BE%E5%87%BD%E6%95%B0f%28x%29%3D%CF%80+sinX%28X%E5%B1%9E%E4%BA%8ER%29%281%29%E8%AF%81%E6%98%8Ef%28x%2B2k%CF%80%29-f%28x%29%3D2k%CF%80sinX%28k%E5%B1%9E%E4%BA%8EZ%29%282%29%E8%AE%BEX.%E4%B8%BAf%28x%29%E7%9A%84%E4%B8%80%E4%B8%AA%E6%9E%81%E7%9B%B4%E7%82%B9%2C%E8%AF%81%E6%98%8E%5Bf%28x.%29%5D2%3Dx4%2F%281%2BX.2%292.%E5%9C%A8%E4%B8%89%E8%A7%92%E5%BD%A2ABC%E4%B8%AD%2C%E2%88%A0C%3D60%C2%B0a%2Cb%2Cc%E5%88%86%E5%88%AB%E4%B8%BA%E2%88%A0A%2C%E2%88%A0B%2C%E2%88%A0C%E7%9A%84%E5%AF%B9%E8%BE%B9%2C%E5%88%99a%2F%28b%2Bc%29%E5%8A%A0b%2F%28c%2Ba%29%E7%9A%84%E5%92%8C%E4%B8%BA%3FThank+you+...%E4%B8%8D)
1.设函数f(x)=π sinX(X属于R)(1)证明f(x+2kπ)-f(x)=2kπsinX(k属于Z)(2)设X.为f(x)的一个极直点,证明[f(x.)]2=x4/(1+X.2)2.在三角形ABC中,∠C=60°a,b,c分别为∠A,∠B,∠C的对边,则a/(b+c)加b/(c+a)的和为?Thank you ...不
1.设函数f(x)=π sinX(X属于R)
(1)证明f(x+2kπ)-f(x)=2kπsinX(k属于Z)
(2)设X.为f(x)的一个极直点,证明[f(x.)]2=x4/(1+X.2)
2.在三角形ABC中,∠C=60°a,b,c分别为∠A,∠B,∠C的对边,则a/(b+c)加b/(c+a)的和为?
Thank you ...
不是f(x)=π sinX而是f(x)=XsinX
I am sorry!
还有类。f'(x)=sinx+xcosx？
1.设函数f(x)=π sinX(X属于R)(1)证明f(x+2kπ)-f(x)=2kπsinX(k属于Z)(2)设X.为f(x)的一个极直点,证明[f(x.)]2=x4/(1+X.2)2.在三角形ABC中,∠C=60°a,b,c分别为∠A,∠B,∠C的对边,则a/(b+c)加b/(c+a)的和为?Thank you ...不
1.(1)f(x+2kπ)-f(x)=(x+2kπ)sin(x+2kπ)-xsinx
=xsinx+2kπsinx-xsinx
=2kπsinx
(2)f'(x)=sinx+xcosx
X为f(x)的一个极直点,则有：sinX+XcosX=0 即tanX=X
f^2(X)=(XsinX)^2=(XtanX)^2*(cosX)^2
=X^4/[(sinX)^2+(cosX)^2]/(cosX)^2
=X^4/(tanX)^2+1
=X^4/(1+X^2)