Wave Power Dissipation: Solving Pozar's Book Problem

[baby_1]

Hello
Here is a problem of Pozar's Book(mircowave).

and here is solution:

my problem is I don't know how he obtain -40.6 because
|T|^2 (T is Reflection Coefficient ) is return power and 1-|T|^2 is transfer powe but 10log none of them return -40.6 , what does -40.6 and how can calculate it?

 

[RUber]

$| \Gamma|^2 = .999956^2 + .0000435^2$
$1 - | \Gamma|^2 = 8.7996e-005$
$10 log_{10} (8.7996e-005) = -40.6$
Perhaps it was the modulus of the complex number that threw you off? Or was it the base10 log?