HP49-50G : tan(x) 50% faster than sin(x) or cos(x)

[Gil]

Interesting possibility.

But using "your" formula for log(x), ie dividing ln(x) by 2.30258509299 [ln(10], the elapsed time is much longer than the direct use of the log command.

By your suggestion, we might say that
tan(x) = sin/cos
tan² = sin²/cos²
tan² = (1-cos²)/cos² = 1/cos² - 1
1+tan² = 1/cos²
—> cos =±sqrt 1/(1+tan²) *

But, again, executing * requires (in a program) a much longer
execution time than the direct cos command.

Regards,
Gil