Question

對于單項(xiàng)式-2πr²的系數(shù)、次數(shù)分別為

1. A.
   -2，2
2. B.
   -2，3
3. C.
   -2π，2
4. D.
   -2π，3

Answer 1

C
分析：根據(jù)單項(xiàng)式的系數(shù)是值單項(xiàng)式的數(shù)字因數(shù)，是-2π；單項(xiàng)式的次數(shù)是指單項(xiàng)式中所含字母的指數(shù)的和，是2．
解答：單項(xiàng)式-2πr²的系數(shù)是-2π，次數(shù)是2，
故選C．
點(diǎn)評：本題考查了對單項(xiàng)式的系數(shù)和次數(shù)的理解和運(yùn)用，注意：單項(xiàng)式的系數(shù)是值單項(xiàng)式的數(shù)字因數(shù)，單項(xiàng)式的次數(shù)是指單項(xiàng)式中所含字母的指數(shù)的和．