(i) y + (2/y)

**No**. No. It can be observed that the exponent of variable y in term 2/y is -1,which is not a whole number. Therefore, this expression is not a polynomial.

(ii) x^{10 }+ y^{3} + t^{50}

**No**. It can be observed that this expression is a polynomial in 3 variables x, y, and t. Therefore, it is not a polynomial in one variable.