Question: the extremities of any diameter on mohr's circle represent

title: Mohr's circle
text: Draw the Cartesian coordinate system ( σ n , τ n ) ( \ displaystyle ( \ sigma _ ( \ mathrm ( n ) ) , \ tau _ ( \ mathrm ( n ) ) ) ) with a horizontal σ n ( \ displaystyle \ sigma _ ( \ mathrm ( n ) ) ) - axis and a vertical τ n ( \ displaystyle \ tau _ ( \ mathrm ( n ) ) ) - axis .