Final answer:
To find the exact value of the expression for a given value of theta, substitute the value of theta into the expression and simplify to obtain the exact value.
Step-by-step explanation:
To find the exact value of the expression for a given value of theta, you need to evaluate the expression using the given value of theta. Substitute the value of theta into the expression and simplify the expression to obtain the exact value.
For example, if the expression is sin(theta) + cos(theta) and the given value of theta is 30°, substitute 30° into the expression: sin(30°) + cos(30°). Use a calculator or refer to a trigonometric table to find the exact values of sin(30°) and cos(30°), which are 0.5 and sqrt(3)/2, respectively. Evaluate the expression to obtain the exact value: 0.5 + sqrt(3)/2.