2011-08-31 21:35:13| 分类: WolframAlpha | 标签: |举报 |字号大中小 订阅
先作图 输入:plot x^3-2x from x=-2 to 2
网址: http://www.wolframalpha.com/input/?i=plot+x%5E3-2x+from+x%3D-2+to+2
解方程求曲线与x轴的交点。输入: solve x^3-2x
http://www.wolframalpha.com/input/?i=solve+x%5E3-2x
求面积: A=int abs( x^3-2x) from -sqrt(2) to sqrt(2)
http://www.wolframalpha.com/input/?i=A%3Dint+abs%28+x%5E3-2x%29+from+-sqrt%282%29+to+sqrt%282%29
另解 直接求面积
输入: area between x^3-2x and the x-axis
http://www.wolframalpha.com/input/?i=area+between+x%5E3-2x+and+the+x-axis
结果有误!
两曲线之间的面积
先作图:plot x^2, x^3
http://www.wolframalpha.com/input/?i=plot+x%5E2%2C+x%5E3
求交点:solve x^2=x^3
http://www.wolframalpha.com/input/?i=solve+x%5E2%3Dx%5E3
另解 直接求两曲线之间的面积
输入: area between x^2 and x^3
http://www.wolframalpha.com/input/?i=area+between+x%5E2+and+x%5E3
求面积:integrate abs(sin(x)-cos(2x)) from x=0 to pi
http://www.wolframalpha.com/input/?i=integrate+abs%28sin%28x%29-cos%282x%29%29+from+x%3D0+to+pi
另解:直接求面积
输入: area between sin(x) and cos(2x) from x=0 to pi
http://www.wolframalpha.com/input/?i=area+between+sin%28x%29+and+cos%282x%29+from+x%3D0+to+pi
很方便!
再补充一个例子
先作图:plot 2-x^2>e^x, x=-2..2< xmlnamespace prefix ="o" ns ="urn:schemas-microsoft-com:office:office" />
http://www.wolframalpha.com/input/?i=plot+2-x%5E2%3Ee%5Ex%2C+x%3D-2..2
求交点: solve 2-x^2=e^x
http://www.wolframalpha.com/input/?i=+solve+2-x%5E2%3De%5Ex
求面积:int 2-x^2-e^x, x=-1.31597..0.537274
输入: integrate (2-x^2-e^x)Boole(2-x^2>e^x), x=-oo..oo
返回《用WolframAlpha做微积分》总目录:
http://xuxzmail.blog.163.com/blog/static/251319162011730102030274/
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