The two focuses of hyperbola x ^ 2 / A ^ 2-y ^ 2 / b ^ 2 are F1 and F2. If P is the upper point and lpf1l = 2lpf2l, the value range of hyperbolic eccentricity is

The two focuses of hyperbola x ^ 2 / A ^ 2-y ^ 2 / b ^ 2 are F1 and F2. If P is the upper point and lpf1l = 2lpf2l, the value range of hyperbolic eccentricity is

Pf1 + PF2 ≥ F1F2
PF1-PF2=PF2=2a,PF1+PF2=3PF2=6a
∴6a≥2c
3 a ≥ C, i.e. e ≤ 3
∴1