Math 中文标题 # 中文内容 # 我是内容1 我是内容2 LaTeX formatted equation: \( E = -J \sum_{i=1}^N s_i s_{i+1} \) If \(a^2=b\) and \( b=2 \), then the solution must be either \[ a=+\sqrt{2} \] or \[ a=-\sqrt{2} \] test math