What's the difference between phase shift and phase angle? [Solved!]

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My text book says phase shift means one thing, my teacher says another about phase angle, and your page says something else.

What is the difference between them? Are they the same?

Relevant page

<a href="/trigonometric-graphs/3-graphs-sin-cos-phase-shift.php">3. Graphs of <span class="noWrap">y = a sin(bx + c)</span> and <span class="noWrap">y = a cos(bx + c)</span></a>

What I've done so far

I've read as much as I can, but don't get it.

X

The use of the term "phase shift" to represent the horizontal shift of a graph is almost universal among high school teachers and text authors at that level, but is, I believe, contrary to the majority usage among university mathematics and physics communities as well as in applied fields. 

While the proposed distinction between "phase shift" and "phase angle" might be one way of saving face for the teachers, I do not think it is appropriate to require students to adopt linguistic conventions that are not essentially universal, and indeed it is better to let them know that some terms are used differently in different professional communities - and then to refrain from having their grades depend on whether they follow one or other of those conventions. 

In my opinion, what high school math teachers do with the notion of phase is worse than having them not mention the topic at all.

X

Hi Alan

Thanks a lot for your comment. I have tweaked those pages a bit, but left my statement on phase angle and phase shift intact, based on feedback from electronics engineering lecturers that I work with.

I have added your comments and a response at:

<a href="http://www.intmath.com/blog/mathematics/phase-shift-or-phase-angle-499">Phase Shift or Phase Angle?</a>

X

Thanks Alan and Murray. It's clearer now.