11.3. Trigonometric Polar Form of Complex Numbers http://www.ck12.org
- 15 cisπ 4 ·2 cisπ 6
13.−2 cis^23 π÷15 cis^76 π
Letz 1 =r 1 ·cisθ 1 andz 2 =r 2 ·cisθ 2 withr 26 =0. - Use the trigonometric sum and difference identities to prove thatz 1 ·z 2 =r 1 ·r 2 ·cis(θ 1 +θ 2 ).
- Use the trigonometric sum and difference identities to prove thatz 1 ÷z 2 =rr 21 ·cis(θ 1 −θ 2 ).