EasyCalc - Quadratic Function

[Douglas]

I would like to see the results of a quadratic equation in the EasyCalc. But how much I type the equation correspondent, appears
an only root. How I make to see the others?

The equation that I type is the following one: 2x^2+3x-2=0

I type in the EasyCalc in this way:
fzero(-100:100:"x(2)*x^2+x(3)*x+x(4)":1E-8:2:3:-2)

The results are: 0.5 and -2. The result that the calculator returns is 1,999...

[Nobody/Anonymous]

I can help you a little bit: Use the solver outgoing from the formula: ax^2+bx+c=0 with 2 formulas: left quadratic equation (lqe) and (rqe)
lqe=-b/2/a-sqrt((-b/2/a)^2-c/a
rqe=-b/2/a+sqrt((-b/2/a)^2-c/a
Enter these 2 formulas into the solver panel and update. Then you have to enter the variables a, b and c. Using lqe you get -2, using rqe you get 0.5 as result of your example. A better solution would be, if the programmers of the super EasyCalc could tell the solver to accept 2 entries, separated by ";" and even 2 formulas in the same way.

[Nobody/Anonymous]

Odrap posted a simple solution for this problem on 2001-08-01 14:19

[Nobody/Anonymous]

Quadratic Equation solved using three functions. 
1) xrpos computes (-b + sqrt(b^2 - 4ac)) / 2a
2) xrneg computes (-b - sqrt(b^2 - 4ac)) / 2a
3) xroot displays a list of {xrpos, xrneg, -b/2a, b^2-4ac, and 2a}

To solve:
x^2 - x - 1;
Use:
xroot(1:-1:-1)
list returns:
1.618033989
-0.618033989
0.5
5
2
The last three items of the list are for reporting answer in the form 0.5 plus or minus sqrt(5)/2

xrpos()="(-x(2)+(sqrt(x(2)^2-4*x(1)*x(3))))/(2*x(1))"
xrneg()="(-x(2)-(sqrt(x(2)^2-4*x(1)*x(3))))/(2*x(1))"
xroot()="list(xrpos(x(1):x(2):x(3)):xrneg(x(1):x(2):x(3)):x(2)^2-4*x(1)*x(3):2x(1))"
xroot()="list(xrpos(x(1):x(2):x(3)):xrneg(x(1):x(2):x(3)):-x(2)/(2*x(1)):x(2)^2-4*x(1)*x(3):2x(1))"