A consequence of this formula is that the sectional curvature satisfies 1 ≤ ≤ K ( σ σ ) ≤ ≤ 4 for all 2-planes σ σ . The maximum sectional curvature (4) is attained at a holomorphic 2-plane — one for which J (σ) ⊂ σ — while the minimum sectional curvature (1) is attained at a 2-plane for which J (σ) is orthogonal to σ. For this reason, the Fubini–Study metric is often said to have "constant holomorphic sectional curvature" equal to 4.