Which of the following expressions is a polynomial in one variable?
(a) x+2x+3
(b) 3√x+2√x+5
(c) √2x2−√3x+6
(d) x10+y5+8
(c) √2x2−√3x+6
Clearly, √2x2−√3x+6 is a polynomial in one variable because it has only non-negative integral powers of x.