Need a free Mathematics Calculator?

Check out Microsoft Mathematics: http://www.microsoft.com/downloads/en/details.aspx?FamilyID=9caca722-5235-401c-8d3f-9e242b794c3a

Microsoft Mathematics provides a graphing calculator that plots in 2D and 3D, step-by-step equation solving, and useful tools to help students with math and science studies.

Microsoft Mathematics can help you with many tasks, including:

• Computing standard mathematical functions such as roots and logarithms
• Solving equations and inequalities.
• Solving triangles.
• Converting measurements from one unit to another
• Computing trigonometric functions, such as sine and cosine
• Performing matrix and vector operations, such as inverses and cross-products.
• Computing basic statistics, such as mean and standard deviation.
• Performing operations on complex numbers
• Plotting 2D and 3D graphs in Cartesian, polar, cylindrical, and spherical coordinates.
• Finding derivatives and integrals, limits and sums and products of series
• Finding, plotting, and solving common formulas and equations.

Source: http://www.ghacks.net/2011/01/17/microsoft-mathematics-now-free-perfect-tool-for-math-science-buffs/