<Dl> <Dd> <Dl> <Dd> m = tan ⁡ (θ) (\ displaystyle m = \ tan (\ theta)) </Dd> </Dl> </Dd> <Dd> and <Dl> <Dd> θ = arctan ⁡ (m) (\ displaystyle \ theta = \ arctan (m)) (this is the inverse function of tangent; see inverse trigonometric functions). </Dd> </Dl> </Dd> </Dl> <Dd> <Dl> <Dd> m = tan ⁡ (θ) (\ displaystyle m = \ tan (\ theta)) </Dd> </Dl> </Dd> <Dl> <Dd> m = tan ⁡ (θ) (\ displaystyle m = \ tan (\ theta)) </Dd> </Dl> <Dd> m = tan ⁡ (θ) (\ displaystyle m = \ tan (\ theta)) </Dd>

What does 45 with a line through it mean