How can you estimate SIN() without using trigonometric functions?

Question

I am curious if it is possible to estimate SIN(), COS(), or maybe even TAN().

Answer 1

Touba M.'s answer is correct.

I would just like to add that in more advanced math, you will prove that

the trig functions sin and cos have power series expansions such that, for example,

sin x = x - (x³/6) + (x⁵/120) + ....(for x measured in radians).

Answer 2

Hi Howard,

Being curious is a excellent point

yes, you can guess

1) recognize the angle is in which quadrant

2) compare with 0, 30, 45, 60. and 90

ex) sin 75?

1) first quadrant.

2) it is greater than sin 60 and less than sin 90

sin 60 = √3 /2 sin 90 = 1

sin 75 is between √3 /2 and 1

BE CAREFUL about the decreasing and increasing function

Another point, there is a table that you can find sin () and .... for any angle. for example sin 15 degree ^, 12min, 34 second !!!!

I hope it is useful,

Minoo