Get direct answers of math problems by a single mouse click!!!

It is often seen that most of Mathematicians when obtain some mathematical result, they think to verify it. Sometimes people are not interested in finding solution of mathematical problems by using different techniques manually , instead they just need the solution and its behaviour e.t.c. For Example: Someone may need solution of a third order system of linear algebraic equations without manually solving it!!!
In such situations one thinks of using some Mathematical softwares or packages which directly provide answers.
I have made some Mathematical Widgets available here which can be fruitful in this regard.
For example: If one needs:

• graph of a function in 2D or 3D (without spending time to manually plot it)
• solution of linear or non-linear equations and inequalities (without going to usual steps to get the same)
• to find determinant, inverse, eigen values and eigen vectors of a square matrix of order 3
• to solve a third order system of linear algebraic equations
• to evaluate limit at some point, derivative(upto tenth order)  and integral of a function
• to find area a under a curve within some finite range (definite integration)
• to find maxima and minima of functions of one or more variables
• to get Taylor's series development of a function about some point
• to plot Bessel's function of any order
• to get solution of a second order linear ordinary differential equation, its plot and Lagrangian
• to measure sample standard deviation
• to calculate coefficient of correlation
• to find linear regression line e.t.c 

then he/she can directly get the results by just a single click of mouse after inputting data.
I hope these widgets will help the followers of this Blog in this respect. I acknowledge those who really made these available on "wolframalpha.com".