Can anyone help me solve this?
Originally Posted by ssmh Cos(2x)=-(√2)/2
Can anyone help me solve this? I kind of sleepy so hopefully I don't make a mistake lol
Ok so you know cos is negative in the 2nd and 3rd quadrant.
Also at 135 degrees and 225
Now just divide 135 and 225 by 2 and it will give you your answer