i have the hp 38g calculator and i cannot find arguments in complex numbers(i find as functions in math>>complex>>ARG etc. but i cannot use properly).For example when i enter this it gives me result 0. For example THIS:
To calculate your example, type the following into the 38g's entry line in degree mode, using the square root symbol where I have "sqrt" and the angle symbol where I have "angle":
(10, angle 45)*sqrt(2)*(10, angle 180)
This returns the complex result of -(100,100) which of course equals -100-100*i. You can then use the ABS and ARG commands on that result to see that it is equal to "100*sqrt(2) at angle -135°" in polar notation.
Hope that helps! Disclaimer: I don't work for HP, but I love their calculators.