Question 1173055: If θ= 2π/3, then
sin(θ) equals:
cos(θ) equals:
tan(θ) equals:
sec(θ) equals: Found 2 solutions by ikleyn, Theo:Answer by ikleyn(53751) (Show Source):
You can put this solution on YOUR website! 2pi/3 * 180 / pi = 120 degrees.
reference angle for 120 degrees is 60 degrees.
sin and cosec is positive in Q1 and Q2
cos and sec is positive in Q1 and Q4; negative in Q2 and Q3.
tan and cot
is positive in Q1 and Q3; negative in Q2 and Q4.
sin(60) = sqrt(3)/2 = .8660254038
cosec(60) = 2sqrt(3)/3 = 1.154700538
cos(60) = 1/2 = .5
sec(60) = 2 = 2
tan(60) = sqrt(3) = 1.732050808
cot(60) = sqrt(3)/3 = .5773502692
that's for the reference angle of 60 degrees.
for 120 degrees, the values are the same, except:
sin and cosec are positive.
cos and sec are negative.
tan and cot are negative.
sin = sine
cos = cosine
cosec = cosecant
sec = secant
tan = tangent
cot = cotangent
the angle in the unit circle would look like this:
the equivalent angle in radians is found by multiplying the angle in degrees by 180 / pi.
60 degrees * pi / 180 = 1/3 * pi = pi/3
30 degrees * pi / 180 = 1/6 * pi = pi/6
120 degrees * pi / 180 = 2/3 * pi = 2pi/3
