2007-10-25 13:18:47 · 4 answers · asked by greenie23510 1 in Science & Mathematics ➔ Mathematics
arcsin -1/2 = -pi/6, etc...
2007-10-25 13:22:10 · answer #1 · answered by UnknownD 6 · 0⤊ 0⤋
You should remember that in a 30 60 90 triangle, the hypotenuse is twice the short leg and the long leg is equal to the short leg * sqrt(3).
So let hypotenuse = 2
Then short leg =1 and long leg = sqrt(3)
Now you can see that the sin 30 = 1/2
So sin -30 = - 1/2
Thus arcsin (-1/2) = -30 degrees
2007-10-25 20:29:27 · answer #2 · answered by ironduke8159 7 · 0⤊ 0⤋
For what value sin is -1/2?
sin(30)=sin(pi/6)=1/2
because you have -1/2 the angle lies in the 3rd or 4th quadrant where sin is negative.
sin(-30) or 330 degrees and the angle lies in the fourth quadrant.
2007-10-25 20:27:00 · answer #3 · answered by cidyah 7 · 0⤊ 0⤋
This done by recognizing that Ï/6 (or 30°) is a special angle
sin(Ï/6) = 1/2
sin(-Ï/6) = -1/2
so sin^(-1)(-1/2) = -Ï/6 or 11Ï/6 (or 330°)
2007-10-25 20:32:33 · answer #4 · answered by Marvin 4 · 0⤊ 0⤋