Without using a calculator, compute the sine and cosine of $\displaystyle \frac{{{4}\pi}}{{3}}$ by using the reference angle.

What is the reference angle? Preview Question 6 Part 1 of 4    radians.

In what quadrant is this angle? (answer 1, 2, 3, or 4)

$\displaystyle {\sin{{\left(\frac{{{4}\pi}}{{3}}\right)}}}=$ Preview Question 6 Part 3 of 4  

$\displaystyle {\cos{{\left(\frac{{{4}\pi}}{{3}}\right)}}}=$ Preview Question 6 Part 4 of 4  

(Type sqrt(2) for $\displaystyle \sqrt{{{2}}}$ and sqrt(3) for $\displaystyle \sqrt{{{3}}}$.)