Question 677073
This should be pretty easy if you can use a calculator (or calculator program on your computer). Just make sure the calculator is set to work in degrees.<br>
If you are supposed to find an exact value for sin(25), then you must find some expression involving special angles (and possibly factors of 1/2 or 2) that is equal to 25. Then you use sin(A+B), sin(A-B), sin(2x) or sin((1/2)x) to find the value you're looking for. For example:
{{{sin(75) = sin(30+45) = sin(30)cos(45) + cos(30)sin(45) = (1/2)(sqrt(2)/2) + (sqrt(3)/2)*(sqrt(2)/2) = sqrt(2)/4 + sqrt(6)/4 = (sqrt(2) + sqrt(6))/4}}}
which is an exact expression for sin(75).<br>
However I am having trouble finding such an expression for sin(25).
There are plenty of expressions that are equal to 25:
45 - 20 (but 20 is not a special angle)
60 - 35 (but 35 is not a special angle)
(1/2) * 50 (but 50 is not a special angle)
2 * 12.5 (but 12.5 is not a special angle)
315 - 290 (but 290 is not a special angle)
(1/2) * (1/2) * 100 (but 100 is not a special angle)
etc.
Perhaps you'll have better luck finding some combination that involves special angles (and possibly factors of 1/2 or 2).