=== Useful online website for undergraduate to check your answers: *How to graph a function online? Goto [[http://www.quickmath.com/webMathematica3/quickmath/page.jsp?s1=graphs&s2=equations&s3=basic|Online grapher]] or [[http://www.wolframalpha.com/|WolframAlpha]] *How to do matrix calculation? Like finding the inverse, eigenvalue, eigenvector and more... Goto [[http://www.bluebit.gr/matrix-calculator|Online matrix calculator]] *Don't know how to integrate, don't know how to find anti-derivative? Goto [[http://integrals.wolfram.com/index.jsp|Online Integrator]] *This site [[http://www.wolframalpha.com/]] knows a lot. ==== If you find any other good math website, please don't hesitate to [[About me|Contact me]].