Question about Texas Instruments TI-84 Plus Calculator

# Polar to rectangular conversion working incorrectly

When I try to convert from polar to rectangular (320e^(-45i)) i get a result of 168.103-272.289i when I should get 226.27 - 226.27i. This is weird because when I do the command (226.27 - 226.71i) >Polar, it will give me the correct answer of 320e^-45i. When I do (168.103-272.289i) >Polar it gives 320e^-58.3i. Is there anyway to fix this? I was pretty sure my calculator was doing this correctly before, but it won't anymore.

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### Stevan Milanovic

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At first, Rect and Polar are a display-format instructions, not a conversion functions. Polar instruction displays complex value in rectangular form a + bi. The complex value can have any complex form. However, an r*exp(i*theta) causes an eror in Degree angle mode according to the TI avowal. See captured images below

Posted on Sep 06, 2012

### k24674

SOURCE: I'm trying to do sin

It is very likely that when you change the angle unit, you are not saving the changes made.
After you finish changing settings, use the TAB key repeatedly to move cursor towards the OK button at the bottom. If you do not confirm changes by clicking OK, they will be lost.

You can also make the changes the default ones by clicking the Make Default option.

Posted on Jul 29, 2011

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## Related Questions:

### How to covert from polar to Rectangular

Let use an example to convert from polar to rectangular. There may be other ways to do it on this particular calculator, but this should work on all calculators.

Let's use 20 degrees and 5 units for our polar.

Sin 20 degrees = y/5, cross multiplying we get y = 5 sin 20 degrees.

Similarly, Cos 20 degrees = x/5. Cross multiplying we get x = 5 cos 20 degrees.

Thus, I get (1.71, 4.70) as the rectangular coordinates of the point.

Good luck.

Paul

Nov 06, 2015 | Canon F-603 Calculator

### Conversion of polar to rectangular form and vice versa

Conversion of polar form to rectangular:
• Switch to CMPLX mode: [MODE] [2]
• Enter complex number in polar form, e.g. r = 3, θ = 42°: 3 [SHFT] [(-)] 42 [=]
• Switch to rectangular view: [SHFT] [2] [4]
Conversion of rectangular to polar:
• Switch to CMPLX mode: [MODE] [2]
• Enter complex number in rectangular form, e.g. real part = 2, imag part = 3: 2 [+] 5 [ENG] [=]
• Switch to polar view: [SHFT] [2] [3]

Jan 12, 2011 | Casio FX991ES Scientific Calculator

### Converting between Forms When working with phasors it is often necessary to convert between rectangular and polar form. To convert from rectangular form to polar form: M = sqrt{A^2 + B^2} f =...

You can switch the display mode for complex numbers by pressing SHIFT MODE down 3 and picking one. This will display the current result in the selected mode.

You can also override the current display mode and specify the format. Add these keystrokes at the end of a calculation: SHIFT 2 then 3 for polar or 4 for rectangular.

Nov 24, 2010 | Casio FX-115ES Scientific Calculator

### What calculator would you recommend for polar and rectangular formula's?

Are you serious?
No calculator purchase should be solely based on such a trivial matter.
But if you are looking for a very good scientific calculator, I would suggest the new Write View EL-W506/W516/W546 calculators by Sharp, or the FX-115ES/991ES Natural Display by Casio.

With these calculators you can see what you enter displayed as in textbooks. Naturally, they all do coordinates conversions from Polar to Rectangular and from Rectangular to Polar.

Jun 17, 2010 | Casio FX-115ES Scientific Calculator

### I've read that the Casio fx-115ES does a great job working with complex numbers, but I haven't found it to be so simple. I am looking for an easy way to convert from rectangular to polar form and back. It...

You can perform coordinate conversions in the COMP, STAT, MATRIX and VECTOR Modes.
Angle unit may be in either degree or radian.

To convert from rectangular to polar, (SQRT(2)/2,SQRT(2)/2)

Press [SHIFT] [+] (Pol)
Screen displays Pol(
Type in SQRT2
Use right arrow to move cursor out of radical
Type in /2 [SHIFT] [,]
Type in SQRT2
Use right arrow to move cursor out of radical
Type in /2
Close the right parenthesis
Screen displays Pol (SQRT2 /2, SQRT2 / 2)
Press [=]. Display echoes the command on top line and result in bottom line as r=1, theta =45, (if unit is in degree) or theta = 0.7853981634 if unit is radian.

To convert from polar to rectangular coordinates
Note: You cannot use the answer memory to convert back to rectangular because the calculator will use the r-value only. So you will have to enter the radius AND the angle.

ex: Rec(1,45)
Angle must be in degree
Press [SHIFT][-] (Rec)
Screen display Rec(
Type in 1 [SHIFT] (,) 45 [)] [=]
Calculator displays X=0.7071067812, Y=0.7071067812
If you press the SD key hoping to convert the decimals to radicals, the calculator will not do it.

As to the "confusion", I have found none.
After you finish entering the argument of a square root, use the right arrow to move cursor out of under the root symbol to signify that the argument is complete. If you use a left parenthesis inside the root, you must insert the matching right parenthesis inside the root, then move cursor outside the root.

This is how the calculator behaves, and I am not expressing an opinion on how simple or complicated that is. I assume that to make full use of the calculator capabilities, one has to converse with it, using the syntax it understands.

Mar 31, 2010 | Casio FX-115ES Scientific Calculator

### TI-84 has problems converting between rectangular and polar. is there a fix for this?

The conversion from rectangular to polar coordinates requires the calculation of an angle . If the angle unit that the calculator is configured for is different from the one you have in mind, you get (not erroneous results) but unexpected ones.
If the angle unit under [MODE] is radian, the angle you get in the conversion is in radians. Similarly, if the angle unit is degree, the angle obtained after coordinate conversion is in degrees.

Feb 19, 2010 | Texas Instruments TI-84 Plus Calculator

### Can you show how to convert pola to rectangular o

Hello,
To avoid errors make sure that the angle unit is THE ONE required by your problem. To verify or to change the angle unit press [SIFT][MODE] and select [3: Deg] for degrees, [4:Rad] for radians, or [5:Grad] for grads.

Convert from rectangular to polar

[SHIFT][+] (Pol) . Screen displays Pol(
You enter the X-coordinate, and the Y coordinate separated by a comma, then you close the parenthesis and press [=].

Exemple: Polar coordinate of the point (1,1)
Pol( 1, 1) gives
r=1.414213562 (square root of 2)
θ=45

Here is how you enter it
Press [SHIFT][MODE][2:LineIO]
[SHIFT][POL] 1 [SHIF] [,] 1 [)] [=]

The screen displays
Pol(1,1)
r= 1.414213562
θ= 45

Convert from polar to rectangular coordinates

Exemple: Recatngular coordinates of (r=3, θ=60°)
[SHIFT][Rec] 3 [SHIFT][,] 60 [ ) ] [=]
The screen displays
Rec(3,60)
X= 1.5
Y= 2.598076211

Hope it helps.

Nov 14, 2009 | Casio FX-115ES Scientific Calculator

### How to convert polar to rectangular form

Hello,
Press [MODE] and select [1:COMP]
Press [SHIFT][MODE] and select [3:Deg]. You can also use rad if the angle you are given is in radians.
To start the conversion
Press [SHIFT][-] (Rec) screen displays Rec(
Key in the radius r , ex: 3 screen displays Rec(3
Press [SHIFT][)] (,) to enter comma separator Rec(3,
Key in the angle in degrees, ex: 57.3; screen displays Rec(3,57.3
Press ) to close parentheses; screen displays Rec(3, 57.3)
Press [=]
Screen displays
Rec(3, 57.3)
X=1.620720961
Y=2.524532346

X and Y are the values of the coordinates.

Rec(3, Pi) gives X=-3, Y=0
Hope it helps

Oct 18, 2009 | Casio FX-115ES Scientific Calculator

### Polar/rectangular

For a TI-86

Converting rectangular to polar
Press "2ND" and then "MORE" for the MODE screen
Highlight PolarC and press "ENTER"
Quit that screen.
A example of converting 5+j6
Enter "(5,6)" in the calculator and press "ENTER"
Should get (7.81024967591*angle*50.1944289077)

Converting polar to rectangular
Press "2ND" and then "MORE" for the MODE screen
Highlight RectC and press "ENTER"
Quit that screen.
A example of converting 5*angle*35
Enter "(5*angle*35)
Should get (4.09576022145,2.86788218176)

Note
*angle* is the symbol when you press "2ND" then ","

Note 2
To round the an decimal places press "2ND" then "MORE" for the MODE screen and on the line that says float, choose a number on that line for the number of decimal places you would like to have.

More can be found at

Dec 02, 2008 | Texas Instruments TI-86 Calculator

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