Dear Student,
Here is the solution of your question.
(a). Given expression is . This is a polynomial of degree two, because all the power of the variable are either a natural number or zero.
(b) Given expression is .
This expression can be written as . Hence the given expression is not a polynomial because the variable has a power involved in it.
(c) The given expression is .
This expression can be written as . Hence the given expression is not a polynomial because the variable has a power involved in it.
(d) The given expression is . Hence given expression is a polynomial as all the power of the variable are non negative integer.
Regards
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