Question

Find the exact value of sin5pi/4

Answer 1

`-(√(2) )/(2)`

Explanation:

Trig unit circle shows -->

`\text{sin}({(5\pi )/(4 ))=-\text{sin}((\pi )/(4) )`

Trig Table of Special Arcs gives -->
`\text{sin}((\pi )/(4) )=(√(2) )/(2)`, therefore:

`sin((5\pi )/(4) )=-(√(2) )/(2)`