Question

How do you solve this without using a calculator

Answer 1

`C)\:\:(\sqrt 2)/( 2 )`

Explanation:

`\sin \bigg( (3\pi)/(4) \bigg) \\ \\ = \sin \bigg( \pi - (\pi)/(4) \bigg) \\ \\ = \sin \bigg((\pi)/(4) \bigg) \\ \\ = (1)/( √(2) )\\\\= (\sqrt 2)/( 2 )`