Find the polar graph coordinates of the point with rectangular coordinates: (-2, 2√3)

a. (4, pi3/3)
b. (4, 2pi/3)
c. (4, 5pi/6)
d. (2, 2pi/3)

r² = x² + y² = 4 + 12 = 16
r = 4

tanθ = y/x = (2√3) / −2 = −√3
θ = 2π/3 or 5π/3
But since (−2, 2√3) is in quadrant 2, then π/2 < θ < π
θ = 2π/3

Answer: b. (4, 2π/3)

Memorize the basics and this a piece of cake.

x² + y² = r²
tanΘ = y/x
Get Θ in proper quadrant.

answer choice is b.