Trigonometric functions as fractions on TI-84 Plus. I know that on the TI-84, you can use mode to change settings to fraction mode. However, when I used trigonometric functions to convert them into fractions, they gave me decimals still. Is there another step you have to take in order to receive fractional answers for trigonometric functions?
E.g. In radians, cos(pi/3), which equals (sqrt(3))/2, but the calculator gives .866025...

The trigonometric functions are examples of transcendental functions, which implies that most of their values are irrational numbers, i.e. cannot be expressed as fractions of integers (more formally called a rational number). However, you can always convert a decimal number to an approximate fraction. For example,
$$\pi=3.1415926535897932384... \approx 3.14159 = \frac{314159}{1000000}$$
and you can simplify that last fraction if you want.
