最速下降/牛顿法 armijo线性搜索 比较 F(x)=x2+2x2-ln(x1x2-1) 迭代次数、步长 精度ε=0.1 σ1=0.4 ρ=0.5-Steepest descent/Newton method armijo linear search compare F (x) = x2+ 2x2-ln (x1x2-1) iterations, step length Precision ε = 0.1 σ1 = 0.4 ρ = 0.5