What is the value of $sin -45^@$ ?

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Answer 1 · 2015-01-10T21:04:43

$sin(-45°)=-sqrt(2)/2$
This is the same as $45°$ but starting clockwise from the $x$ axis giving you a negative value of the $sin$ :

or, if you like, is equal to a positive angle of $360°-45°=315°$

(Be careful that for example $cos(-45)=sqrt(2)/2>0$ )

What is the value of sin -45^@sin -45^@?