Category Archives: Conventions

Q: Why radians?

Physicist: Because calculus. When you first start doing trigonometry the choice between radians, degrees, turns, or hexacontades is a matter of personal preference.  Most people use degrees because most other people use degrees (and other people seem pretty on the … Continue reading

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Q: Where do the rules for “significant figures” come from?

Physicist: When you’re doing math with numbers that aren’t known exactly, it’s necessary to keep track of both the number itself and the amount of error that number carries.  Sometimes this is made very explicit.  You may for example see … Continue reading

Posted in -- By the Physicist, Conventions, Equations, Math | 1 Comment

Q: Where do the weird rules for rational numbers come from? (Dealing with fractions)

The original question was:  Why is it when we multiply fractions we multiply the numerators across  and the denominators across?  Whereas when we divide we don’t do the same?  Who came up with these rules and why do they work … Continue reading

Posted in -- By the Physicist, Conventions, Math | 7 Comments

Q: How are imaginary exponents defined?

The original question was: How do you do xi (x to the i power), and how on Earth was it developed?  There isn’t really anything to base xi on from previous rules of exponents as it is a completely new … Continue reading

Posted in -- By the Physicist, Conventions, Equations, Math | 29 Comments

Q: Can you fix the “1/0 problem” by defining 1/0 as a new number?

The original question was: I’ve been relearning some things about imaginary numbers and the concept behind the number got me thinking about something else. Is there a reason that the quantity could not be defined in a similar way to … Continue reading

Posted in -- By the Physicist, Conventions, Logic, Math | 24 Comments

Q: How do you calculate 6/2(1+2) or 48/2(9+3)? What’s the deal with this orders of operation business?

Mathematician: Now that the Physicist and I have answered questions like these ones at least 9 times via email, I figure we should get this horrible topic out of the way once and for all with a short post. The … Continue reading

Posted in -- By the Mathematician, Conventions, Math | 172 Comments