Equal sign with a triagle above it?

1. Mar 12, 2004

frankR

In my EM text book it uses a equal sign with a triangle on top to define the intrinsic impedence of a lossless medium.

I think it means definition but I'm not certain.

The text is 2004 edition of author Ulaby titled Fundametals of Applied Electromagnetics, pg. 265.

Thanks

2. Mar 12, 2004

jamesrc

You're right. This symbol: $$\triangleq$$ means that it is equal to by definition.

I've also seen the three lined equal sign, $$\equiv$$, used in definition statements.

3. Mar 13, 2004

Thanks.