how do i find sin and cos from an angle like -3pi/4

Question

phi · Answer

I would change it to degrees  (easier for me to think about)
then sketch the angle on graph paper

phi · Answer

Then find the "reference angle"  which will be the acute angle it makes with the x-axis

anonymous · Answer

i know it equals -135 degrees but i am confused if the cos and sign would be (-sqrt2/2,sqrt2/2) or (-sqrt2/2,-sqrt2/2) because wouldnt you just got the clockwise when dealing with negative degrees and 135 degrees would put you in the third quadrant?

anonymous · Answer

**-135 degrees would put you in the third quadrant?

phi · Answer

yes, -135 means start at the positive x-axis and go clockwise
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