Compute , where .

Answer and explanation

Correct answer: D.

  1. Step 1: Expand: . Step 2. Replace by : . **Answer: . Why not the others:** the other answers use the wrong sign for , skip the cross terms, or mis-combine the imaginary terms.

Practise more Mathematics A: Functions, Calculus, Complex Numbers and Probability.

Free questions with an explanation for every one, and full timed Exames Nacionais Secundário (Portugal) mock tests.

All Mathematics A: Functions, Calculus, Complex Numbers and Probability questionsTake a mock test

More Mathematics A: Functions, Calculus, Complex Numbers and Probability questions