Which of the following are polynomials :
(i) `3x^(2)-7x+6 " " (ii) x^(2)-sqrt(3)x+4 " " (iii) 3sqrt(x)+5 " " (iv) 13 " " (v) a+(5)/(a)+6`

Explanation

To determine which of the given expressions are polynomials, we need to recall the definition of a polynomial. A polynomial is an expression that can be written in the form:

\[ P(x) = a_n x^n + a_{n-1} x^{n-1} + ... + a_1 x + a_0 \]

where:
- \( a_n, a_{n-1}, ..., a_1, a_0 \) are constants (real numbers),
- \( n \) is a non-negative integer (0, 1, 2, ...),
- The powers of \( x \) must be whole numbers (non-negative integers).
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