David determines that 3√2cis(7pi/4)=-3+3i. When he considers the graphical representation of these numbers, he knows he made an error. Clearly explain in complete sentences what David observed, and where David made his mistake. State the correct rectangular equivalence of 3√2cis(7pi/4)
+23246 The correct rectangular equivalene of 3sqrt(2)·cis( 7pi/4 ) is:
3sqrt(2)·cos( 7pi/4 ) + i·sqrt(2)·sin( 7pi/4 ) = 3 - 3i
As to what he did wrong: he probably interchanged the sin function and the cos function when he was doing
the problem or interchanged the values for sin and cos.
