iPhone Giveaway of the Day - Formula Calc+

1. This calculator can be calculated by inputting the formula unlike a usual calculator.
2. The variable can be used in the formula. You can use alphabet(a-z) and greek alphabet(α-ω) as the variable. If this function is used, for example the following equations will be created,

a*x*y + b*y + c*z + 10

you can perform changing and re-calculating the value of a variable later simply.

3. You can edit formula with moving caret.
4. You can create the simple graph(the division by zero is not supported) by using the created formula.
5. You can send the created formula with mail.
6. You can solve simultaneous equation like the followings,

case1:Solve 1 unknown linear equation.
a*x = b

case2:Solve 2 unknown linear equation.
a1*x + b1*y = c1
a2*x + b2*y = c2

case3:Solve 3 unknown linear equation.
a1*x + b1*y + c1*z =d1
a2*x + b2*y + c2*z =d2
a3*x + b3*y + c3*z =d3