You’re not wrong. This post wasn’t really meant literally.

Speaking in the language of the post:

Well, look. Let’s put to the side whether or not sin^2x + cos^2x is actually 1 or not. In today’s culture, the obvious and natural interpretation of what you said is that sin^2x—cos^2x = 0. But that’s a damaging belief for the future engineers of America to have, that could seriously harm their faith in the math education they received at our upstanding public schools, and so it’s irresponsible for you to go around saying “sin^2x + cos^2x = 1” without clarifying exactly what you do or don’t mean.

I hear your concern for our future engineers! They should have the best educational opportunities we can offer them, and I’m not it! Fortunately, I have no plans to go into teaching. Rather, I thought that the context of the discussion up to that point was sufficient to make clear what I meant by “sin^2x + cos^2x = 1”, and not imply anything “= 0″ that doesn’t.
Unfortunately, I’ve noticed the conversation drifting from the point I was trying to make (which I was making an effort to support). I meant to be addressing...

You’re not wrong. This post wasn’t really meant literally.

Speaking in the language of the post:

Well, look. Let’s put to the side whether or not sin^2x + cos^2x is actually 1 or not. In today’s culture, the obvious and natural interpretation of what you said is that sin^2x—cos^2x = 0. But that’s a damaging belief for the future engineers of America to have, that could seriously harm their faith in the math education they received at our upstanding public schools, and so it’s irresponsible for you to go around saying “sin^2x + cos^2x = 1” without clarifying exactly what you do or don’t mean.

I hear your concern for our future engineers! They should have the best educational opportunities we can offer them, and I’m not it! Fortunately, I have no plans to go into teaching. Rather, I thought that the context of the discussion up to that point was sufficient to make clear what I meant by “sin^2x + cos^2x = 1”, and not imply anything “= 0″ that doesn’t. Unfortunately, I’ve noticed the conversation drifting from the point I was trying to make (which I was making an effort to support). I meant to be addressing...