posted by Sam .
Evaluate the sine, cosine and tangent of -7pi/3. I got 1/2, sq. root of 3/2 and sq. root of three. My book says the sine and the tangent are negative, but I don't know why? Can you explain the rule??
what quadrant is it in?
2PI-7PI/3=2PI-2.333Pi=-1/3 PI which is in the fourth quardrant. Sin, tan is negative.