Derivative Step-by-Step for Android

A calculus based learning app. This app shows step by step differentiation of any expression. As an usage example there is one sample input available when app is launched . Input consists of two parts - Expression,variable where Expression refers to the expression to be differentiated. For example sin(x)+tan(x-1),log(t*x) etc. And variable refers to the variable with respect to which the differentiation is to be carried out. Example x,y,t etc. E refers to exponential 'e'. Usage Examples: sin(x)+tan(x),x log(x+log(asin(x))),x 2x/3,x E^sin(x)*atan(t),t asinh(E^x),x s1*x^3+3,x acot(x+1)+acosec(x),x ..... etc