# Trig

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How do I use the unit circle to evaluate tan(-3pi/4)

• Trig -

draw the circle and the line at the given angle. The intersection will give you a point (x,y).

in this case, the line is at an angle of 45 degrees, in QIII, where y=x.

tan (-3pi/4) = (-1√2)/(-1/√2) = 1

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