Let (-3, 0) represent A and (0, [tex] \sqrt{7} [/tex]) represent B.
[tex] d_{AB} =\sqrt{(-3 - 0)^{2} +(0 - \sqrt{7})^{2}} [/tex]
[tex] d_A_B} =\sqrt{(-3)^2 + (- \sqrt{7} )^2} [/tex]
[tex] d_A_B} =\sqrt{(9 +7)} [/tex]
[tex] d_A_B} =\sqrt{(16)} [/tex]
[tex] d_A_B} [/tex] = 4
Answer: 4 units