Hi, I ws playing around with my calculator and Ive put it in a complex number mode.

When I try to solve a cubic equation, all of the solutions are in complex numbers, when they shouldnt be.

Is there anything that I can do about this to stop my answers being complex numbers when solving cubic equations?

Thanks

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"Is there anything that I can do about this to stop my answers being complex numbers when solving cubic equations?"

You are making an assumption that is unwarranted.Namely that a cubic equation must necessarily have 3 real roots. This is not the case.

Let your equation be

If coefficients are complex you should expect some complex roots. Right?

If the coefficients are REAL then depending on the discriminant

you can have three cases

DELTA positive : three distinct real roots

DELTA=0 , the equation has a multiple root and all roots are REAL

DELTA negative: the equation has ONE real root and 2 complex roots that are complex conjugate of each other.

It suffices to look at the Tartaglia/Cardano expressions of the roots to know that more often than not there is going to be compIn complex number mode, how to get out? - d64abc4.jpgbr />

Posted on Jul 25, 2010

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Posted on Jan 02, 2017

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It does not solve complex number equations. You can do simple calculations on complex numbers: addition, multiplication, etc. But nothing fancy.

Oct 26, 2015 | Casio Office Equipment & Supplies

Put the calculator in complex Mode. Enter a complex number and press the key for the operation you want to perform, + for addition etc.

Oct 14, 2015 | Office Equipment & Supplies

Set the Real/Complex mode to COMPLEX. (rectangular coordinates). See the screen captures that follow.

Sep 11, 2014 | Texas Instruments TI-84 Plus Silver...

Is it complex or matrix? You can have only one mode at a time.What kind of equations? The solve function uses real-valued equations.

Complex numbers: You can add, subtract, multiply and divide. You can convert a number from rectangular to polar forms and vice-versa; you can calculate the absolute value of a complex number, or a conjugate.

All the operations are done in the Mode CMPLX.

Complex numbers: You can add, subtract, multiply and divide. You can convert a number from rectangular to polar forms and vice-versa; you can calculate the absolute value of a complex number, or a conjugate.

All the operations are done in the Mode CMPLX.

Feb 04, 2014 | Casio FX991MS Scientific Calculator

There must be an error in what you report. You pressed MODE then 4: Base-N and now your calculator is in base-N calculation mode (the DEC, Hex, BIN, OCT) numeration keys are active.

To do statistics you must put the calculator in STATS mode.

Press MODE: You have 6 computational modes to choose from

1: COMP, the general computational mode

2:CMPLX, for calculation s with complex numbers,

3: STAT for statistics,

4: Base-N, binary, octal, decimal, and hexadecimal numeration

5: Equation, solving mode, etc..

**For statistics, choose 3:STAT**

To do statistics you must put the calculator in STATS mode.

Press MODE: You have 6 computational modes to choose from

1: COMP, the general computational mode

2:CMPLX, for calculation s with complex numbers,

3: STAT for statistics,

4: Base-N, binary, octal, decimal, and hexadecimal numeration

5: Equation, solving mode, etc..

Apr 24, 2012 | Casio FX-115ES Scientific Calculator

At first,
you can enter a complex number in r*exp(i*theta ) form.
This is exponential form of complex number. However, use this form in Radian
angle mode only. It causes a Domain
error in Degree or Gradian angle mode. To resolving this problem type Mode then
F1 and set up Radian mode

Jan 23, 2012 | Texas Instruments TI-89 Calculator

By default the calculator only works with real numbers. To use complex numbers, press MODE 2 to switch to complex mode.

Dec 13, 2010 | Casio FX-115ES Scientific Calculator

Hello,

You perform all calculations in complex mode. When you need to convert to angle amplitude, in the [RUN] screen press [OPTN][F3:CMPLX]

To obtain the angle press [Arg] ( complex number) [EXE]

To obtain the magnitude, amplitude press [Abs] (complex number) [EXE].

Since the [ANS] memory keeps only the last value calculated, you may have to store your result (the complex number) in a variable.

1+ 1 i [white right arrow under tan key to store] [ALPHA] H

Display shows 1+1i. Then

[Abs] [ALPHA] H [EXE] gives 1.414213562

[Arg] [ALPHA] H [EXE] gives 45

Hope it helps.

You perform all calculations in complex mode. When you need to convert to angle amplitude, in the [RUN] screen press [OPTN][F3:CMPLX]

To obtain the angle press [Arg] ( complex number) [EXE]

To obtain the magnitude, amplitude press [Abs] (complex number) [EXE].

Since the [ANS] memory keeps only the last value calculated, you may have to store your result (the complex number) in a variable.

1+ 1 i [white right arrow under tan key to store] [ALPHA] H

Display shows 1+1i. Then

[Abs] [ALPHA] H [EXE] gives 1.414213562

[Arg] [ALPHA] H [EXE] gives 45

Hope it helps.

May 22, 2009 | Casio CFX 9850GB Plus Calculator

Hello,

I do not understand what you mean by solve complex equations, but if you want to manipulate complex numbers here are the tools you need to enter your complex numbers. Operations and function evaluations do not need special symbols.

Hope it helps.

I do not understand what you mean by solve complex equations, but if you want to manipulate complex numbers here are the tools you need to enter your complex numbers. Operations and function evaluations do not need special symbols.

Hope it helps.

Oct 31, 2008 | Casio FX-9860G Graphic Calculator

x^2+5x+7 won't factor any more.. if you're trying to solve it, do:

solve(x^2+5x+7=0,x)

solve(x^2+5x+7=0,x)

May 15, 2008 | Texas Instruments TI-89 Calculator

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