Prove that the distinct complex numbers z1, z2, z3 are the vertices of an equilateral triangle if and only if z1^2 z2^2 z3^2=z1 z2 z2 z3 z3 z1 .

Nikon Z6 II Autofocus Test: A Solid Improvement Over the Z6

SOLVED: Consider the linear regression model y = b0 b1x b2x^2, where x^2 is an endogenous regressor. Using two qualified instrumental variables z1 and z2 for x^2, the first-stage estimation of TSLS is:a. x^2 on 1, x, z1, and z2b. x on 1, x^2, z1, and z2c. x^2 on 1, z1, and z2d. x^2 on 1, x, z1, and z2