# Relationship between theta and theta v theta i

#### Braeden Hamson

Feb 18, 2016
234
Hi guys, I'm working with AC circuits. I have the equations for avg power and reactive power. P and Q resp. Those equations have a compent sin/cos (theta v - theta I) . Additionally P Q and S (complex power) form a triangle whose angle PS is Theta. Is theta=theta v - theta I?

I feel like this is really obvious but I need a sanity check.

#### Ratch

Mar 10, 2013
1,097
Hi guys, I'm working with AC circuits. I have the equations for avg power and reactive power. P and Q resp. Those equations have a compent sin/cos (theta v - theta I) . Additionally P Q and S (complex power) form a triangle whose angle PS is Theta. Is theta=theta v - theta I?

I feel like this is really obvious but I need a sanity check.

There is no theta v or theta i. If you find it in a textbook, show me. Q = S * Sin(theta) and P = S * Cos(theta) . It is a simple right triangle.

Ratch

#### Braeden Hamson

Feb 18, 2016
234
I will as soon as I get a chance