小天使我找到了OG里面对80题里面polynomial to ...degree的描述,可是还是没想出来怎么证明条件2 QAQ
The expression 19x2 - 6x + 3 consists of the terms l 9x2, -6x, and 3, where 19 is the coefficient of x2,-6 is the coefficient of x1, and 3 is a constant term (or coefficient of x0 =1). Such an expression is called a second degree (or quadratic) polynomial in x since the highest power of xis 2.