Question

if Z = Cos x + i sin X Find \[\frac{z^2-1}{z^2 + 1}\]

Answer 1

multiply num and denum by \(\overline{z}\)

Answer 2

and note that \(|z|=1\)

Answer 3

another hint : \(z\overline{z}=|z|^2=1\)

Answer 4

come on yahoo!!!!

Answer 5

\[\frac{(z^2 -1)(cosx-isinx)}{(z^2 + 1)(cosx-isinx)}\]

Answer 6

lol....i was out for 10 min.. Sorry

Answer 7

np

Answer 8

\[\frac{z^2-1}{z^2 + 1}=\frac{z^2\overline{z}-\overline{z}}{z^2\overline{z} + \overline{z}}=\frac{zz\overline{z}-\overline{z}}{zz\overline{z} + \overline{z}}\]

Answer 9

Oh....u told...like..this....)

Answer 10

(z-z1)/(z+z1)

Answer 11

yes and now simplify it

Answer 12

i tanx

Answer 13

Thxx...)))