We sort of had a math class integrated with grammar lessons during one of our board works. We’re asked to solve for a given problem in front of a white board and explain how we came up with the answer afterward.
After the board work, our professor wrote three sentences, including one mathematical expression, on the board.
sin2? = 2sin?cos?
The sine of two theta is equals to two times the product of the sine of theta and the cosine of theta.
The sine of two theta is equal to two times the product of the sine of theta and the cosine of theta.
The sine of two theta is two times the product of the sine of theta and the cosine of theta.
Then, she crossed out the first sentence containing is equals to.
A tacit confession followed. For some unknown reasons, we used to say “is equals to” rather than “is equal to” or simply “is”. I think it’s a by-product of our inarticulateness when we’re still young wherein we say “Three plus four is equals to 7″ or worse, “Four minus two is equals to…ahmm…equals to…”.
Now that I’m in higher mathematics (Calculus and Analytic Geometry), I say
The length of the latus rectum of a parabola is equal to four times the length of the distance of its focus to its vertex.
The limit of the function f (x) as it approaches a is L.
The bottom line is that mathematics helps us be better speakers and good problem solvers while causing us innumerable nosebleeds in the process.