I m usinf casio fx-300 Es calculator. is it possible to do polar addition or subtraction without changing to rectangular form?

Change mode to 1:COMP

Sorry, It is not possible to solve equations on the Casio FX-82 ms. Try the Casio FX-115 ES/ FX-115 ES Plus, FX-991ES/ FX-881 ES Plus C.

If one or both numbers are in polar form, convert it/them to rectangular. Once both numbers are in rectangular form, simply add the two components separately: Add the two x components together, and add the two y components together.

If you're asking how to do this on a particular calculator, please specify the make and model.

No!! The only complex number operations you can perform are addition, subtraction, multiplication, and division and raise to an integer power with positive exponent. You can also get the Argument or the conjugate of a number, convert a complex number from rectangular to polar forms and vice versa.
As to matrices, it can only handle up to 3X3 dimension with real coefficients.

To convert from Polar to Rectangular
PRESS [SHIFT and -Rec] then enter the coordinate and angle
e.g. [SHIFT and -Recl]
Rec(15,0)=
r=15
0=0

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]
  

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.

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.

Use the Rec function (shift of the - key).

Rec(r,t) converts a polar value of magnitude r and angle t in the current angular mode. The real value is assigned to X and the imaginary value is assigned to Y.

Use the Pol function (shift of the + key) for the reverse.

It's on page E-37 of the manual. If you've misplaced your manual, you can download a new one from http://www.casio.com/support/manuals

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

Rec ( radius, angle) =

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.