7 replies to this topic

[TomL_12953]

I have an Algebra FX 2.0 Plus and am trying to use the solve function to solve the following equation:

x^2 + x + 1 = 0

I know it has no real roots but the calculator should give me the imaginary roots. I have the Complex mode set to a+bi. I get the "Can't Solve!" error no matter what starting point I try. Does this work on anyone else's FX 2.0 Plus calculator?

solve(x^2+x+1,0)


Tom Lake

[CrimsonCasio]

you may have complex mode set to a+bi in normal mode, but the calc has a diffrent setup in cas and algebra mode, hit CTRL' />+F3' /> while in Cas/Algebra then go to answer type and hit F2' />.

[BiTwhise]

You have a syntax error..

try:

Solve(X^2+X+1=0,X)        //Solve( expression, variable to solve for ), defualt var is X so it can be omitted

[CrimsonCasio]

thats not a sentax error, I got it to work on my calc by doing what I said.

[BiTwhise]

he wrote "solve(x^2+x+1,0)"
in CAS mode, this is syntax error

in Comp mode, it's not, but you can't imaginary roots in comp mode (approximiation, by Newton/Raphson if I'm not wrong)
for numerical solving he could use the equation program..

[CrimsonCasio]

oh, ok I didn't see the second equation he wrote, i was looking at the first one.

even so the equation will evaluate to no solution unless he does as I said and swicthes to complex mode.

[ross8653]

use the simotanous solver

[XYZ]

Solving for x "...=0,x) gives x = +/-(sqr(3)i/2-1/2 in CAS.

If you try to solve x.x+x+1,0 the calc will give a syntax error. You need to tell it 1)What the expression is equal to and 2)Which variable to solve for.

And sorry for being pedantic but you can't have complex roots really, just factors of an expression

The solver only works with real roots unfortunately...

Oh you can also use rFactor(x.x+x+1) to give the complex factors. Have fun!