handyCalc is first be designed a symbolic calculate system to handle some complicated mathematica features. You can:
The most common situation is solve one equation with one symbol. For example, x+1=2. Of course you know what x is. So let’s try something.
Notice that there is a equals inside that expression. Don’t press your big equals button on your keypad. Flip to the next keypad and there is a smaller equals.
There are two equals on your second keypad. They are different. The big one means “Solve it and give me the answer”. While the smaller one is the real equals. It gives you a “=” on your input. And that is essential to solve equations.
Now after you input your equation, just press the big equals button. The result will be shown directly.
This equation is more complicated than the first one. handyCalc use a method based on Newton method to find it’s root (since v0.3). But as you see, there is a chance that some roots are left behind. In such cases, you can just click the “Show graph and explicit root area” and aim at the cross point of two graphs as shown below. handyCalc will find the most nearest root as you give.
Okay, now let’s try some equation sets.
Notice you have three lines, each line contains one equation. Goto a newline by press the return button on the second keypad or return key on your keyboard. And again, when you finish input, press the equals to solve it.
Variable is a symbol that you store a value in it. Like the [M+] function on most calculators. The “ans” mentioned in Basic tutorial is a variable, too.
With variables, you can do a lot of things in an easier way.
It’s the Einstein’s famous formula. The first line define the variable m, and the second line define the variable c. c is a constant of light speed in m/s. You probably do not change it. m is the mess. Each time I want to change the mess, I just have to go to the first line, and change it instead of change the formula in the third line. Notice that there is a forth line with a single symbol E. that means just output the E as the answer. Of course you can delete it, but the handyCalc will output every single variable you have defined which is not what you want at this time.
The variable will be existed even you flip to the next page or a previous page. But how to remove that variable? Two ways, you can go to the Document menu and press [New], and you get a new document. And you can go to the Tools menu and press [Variable & Function].
And you have all your variables.
You can define your own functions. It’s similar with define a variable. Let’s try it.
It’s a physics formula which calculate the speed when an object fall from h meters height and hit the ground. The g(gravity)=9.8, and V(3) give you the speed when it’s fall from 3 meters height.
And now you have the V(h) function, and you have the acceleration(g=9.8). You can make a T(h) function which calculate how many time it takes to fall to the ground from h meters height.
Graph is easy in handyCalc. Just type your expression and there will be a [Draw graph] below.
Press it and the graph is shown. It maybe a bit small in the first time to plot more areas of the graph. You can zoom in (just click the graph or the zoom in button) to make the graph clear and drag the graph to navigate as you wish.
Also, you can plot multi-graph in one time. Just input multi-line expressions and the graph will be shown in different colors.
NOTICE: when graphing, handyCalc needs a lot of calculation which will slow down your handset.