Originally Posted by aeh
My PG sib, who is a STEM worker, never "memorized" trig identities, because it was more efficient to re-derive them from the law of sines and law of cosines than it was to brute-force memorize them, and then retrieve them from the arbitrary storage location that would have resulted from rote memorization.


Is this unusual? I didn't memorize them either, except sin^2+cos^2=1 and the definitions of tan, sec, and csc.