Question

Which of the following sum of angles is useful in evaluating the trigonometric expression?

Answer 1

SOLUTION:

Case: Trigonometry (double angles)

Given:

$sin(\frac{17\pi}{12})$

Required: To select a sum of angles is useful in evaluating the trigonometric expression

Method:

Check the options that can be simplified to any image in the picture:

First we evaluate the angle in such a way that it forms a special angle

$sin(\frac{17\pi}{12})$

Testing

Option A can be reduced to

$\frac{5\pi}{4}+\frac{\pi}{6}$

Option E can be reduced to:

$\frac{2\pi}{3}+\frac{3\pi}{4}$

Option F can be reduced to:

$\frac{\pi}{4}+\frac{7\pi}{6}$

Final answer:

Options A, E and F are correct