Cyclohexene oxide is treated with methanol containing a catalytic amount of $\mathrm{H}{}_2\mathrm{SO}{}_4$. The major product is

Acid protonates the epoxide oxygen, and methanol attacks from the face opposite the C-O bond, which opens the ring with inversion at that carbon (anti opening). The product has the methoxy and hydroxyl groups on opposite faces, i.e. trans, and forms as a racemic pair.