TI-Nspire CX II 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.
Press → 7: Settings & Status → 2: Document Settings. Confirm Angle = Radian so the eiπ/4 term is read correctly, and set Real or Complex to Rectangular: without this the calculator stays in Real mode and either refuses to combine the terms or returns an error instead of an a+bi answer.
From the Scratchpad calculator, type the base 1+2i in parentheses: → highlight i → . Then raise it to the third power with . The right arrow moves the cursor back out of the exponent.
Subtract the polar term 4eiπ/4: → highlight π → → highlight i → . The ÷ builds a stacked fraction π/4; the first exits it and the last one leaves the exponent.
Press to force the decimal approximation. (Plain would keep the exact surd form of the eiπ/4 term instead of a clean a+bi value.)
(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.