Mathway: Solve Math Problems Quickly
This unique site solves mathematical problems online. The problems could be basic maths, pre-algebra, algebra, geometry, trigonometry, calculus, statistics, linear algebra and more! 
Just enter your problem in the box and click on Evaluate, and up pops the answer! Very cool for school and college kids and engineering students who need to evaluate complex problems in a jiffy. 
Apart from solving maths problems, you have a section on graphs where you can do step-by-step graphing, linear equations and functions, etc. You can also create maths worksheets for use in a class (if you are a teacher). And, finally, there is a Glossary section where you could get definitions of various mathematical terms.
They have also launched an app on Android which does not require Internet access to run. The basic modules are free, but if you wish to see the actual logic and calculation, you have to pay a small fee. Ideal for teachers and students alike. But NOT recommended for cheating at school because actually knowing maths is very important for times when you don’t have Internet access to get to this site, especially in your examination hall!
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