Casio fx-CG50 field manual for IB Math
Complex-number arithmetic
Evaluate any numeric complex expression (sums, products, quotients, integer powers, and mixed Cartesian / polar terms) straight off the home screen, provided it contains no unknowns.
Compute (1+2i)3−4eiπ/4 and write the answer in the form a+bi.
From the MAIN MENU, open Run-Matrix (icon 1). Press to open SET UP, set Angle = Rad and Complex Mode = a+bi (press on that row). Press to return to Run-Matrix. Rad mode is what makes the eiπ/4 term read correctly.
Type the Cartesian power (1+2i)3: i . Insert the imaginary unit with (COMPLEX) (i).
Subtract the polar term 4eiπ/4: i . Here pastes e^( and is π; use for the i.
Press to evaluate. With Complex Mode = a+bi the Casio folds the power and the polar term into a single Cartesian value; press once if it surfaces an exact form rather than the decimal.
(1+2i)3−4eiπ/4≈−13.8−4.83i.
Your turn
Work each one on your calculator, then check the answer.
- 1
Compute (2+i)4 in the form a+bi.
- 2
Compute 2+i9−8i in the form a+bi.
- 3
Compute 2eiπ/4+5ei2π/3, giving the answer in polar form reiθ.