What are the coordinates of the point that corresponds to −7π on the unit circle?
(−2√2, 2√2)
(2√2, −2√2)
(2√2, 2√2)
(−2√2, −2√2)
Let cos(−θ)=−35cos(−θ)=−35 and tanθ>0 .
What is the value of sin(−θ)?
4/3
−3/5
4/5
−4/5
+128407 -7 pi is the same angle as + pi ...... on the unit circle, the coordinates are (-1, 0)
cos(−θ) =−3/5 tan θ > 0
Note that cos(-θ) = cos (θ) ....so....this angle is is in the 3rd quadrant.......so....the sin (-θ) is
y / r = - √ [5^2 - (-3)^2 ] / 5 = - √ 16/ 5 = - 4 / 5
