+1904 \(sin(10^*)\)
I asume you mean \(sin(10°)\). The only way to find the exact value is to plug the expression into a calculator.
\(\pi/18\)
If the expression is one that is on the unit circle that is memorized such as \(sin(45°)\), that is one you should already know which is \(\sqrt(2)/2\).
There are excepions. If there is an expression on the unt circle that is not eaisly memorized but you can mapulate it so that you can change the expression into two seperate expressions that you do have memorized or an expression on the unit circle that is not eaisly memorized but you can mapulate it so that you can divide the expression you know by 2, then you can do it without using a calculator. I would explain it more but that would require a lot of typing, In order to understad more of what I am talking about, go to the following web address: http://www.mga.edu/arts-sciences/docs/math/Math_Resources_Trigonometric_Formulas.pdf. Look at the formulas under the headings Half Angle Formulas, Sum and Difference Formulas, Product to Sums Formulas, and Sum to Products Formulas. If you still need help, ask on this forum and either I or someone else may help you.
