If the non-zero complex numbers α and β correspond to a, B and O on the complex plane respectively as the origin, and α ^ 2 - √ 3 α β + β ^ 2 = 0, then the shape of △ AOB is

If the non-zero complex numbers α and β correspond to a, B and O on the complex plane respectively as the origin, and α ^ 2 - √ 3 α β + β ^ 2 = 0, then the shape of △ AOB is

If β = 0, then α = 0, then △ ABO is a point
When β ≠ 0 = > (α / β) &# 178; - √ 3 α / β + 1 = 0
=>α / β = (√ 3 ± I) / 2 = > | α / β | = 1, and Arg (α / β) = ± π / 6
The vertex angle of the isosceles triangle is π / 6
That is, AOB = π / 6, Ao = Bo

In the complex plane, the distance between the point corresponding to the complex number 21 + I and the origin is ()
A. 1B. 2C. 2D. 22

21 + I = 1-I, then the point corresponding to 1 + I is (1,1), and the distance to the origin is 2

Distribution of roots of quadratic equation
Geometric method algebraic method
The equation has two positive roots
2 has two negative roots
Both real roots are greater than k
Both real roots are less than k
One of 5 is greater than K and the other is less than k
The two real roots of equation 6 are in (m, n)
Only one of the two real roots of the equation is in (m, n)
The equation has two equal roots in the interval (m, n)
Two of the 9 equations are in (m, n) and (P, q) respectively

If the equation is f (x) = 0 and the quadratic coefficient is positive
1 \ \ discriminant > = 0
Axis of symmetry > 0
f(0)>0
2 \ \ discriminant > = 0
Axis of symmetry 0
3 \ \ discriminant > = 0
Axis of symmetry > k
f(k)>0
4 \ \ discriminant > = 0
Axis of symmetry 0
5\ f(k)=0
m0
7-discriminant > = 0
f(m)f(n)