考點(diǎn):多項(xiàng)式
專題:
分析:此多項(xiàng)式共五項(xiàng):3x2、-y、-xy3、x3、-1.最高次項(xiàng)為-xy3;
解答:解:由上面分析得多項(xiàng)式3x2-y-xy3+x3-1中最高次數(shù)項(xiàng)是多項(xiàng)式-xy3;
故答案為:-xy3.
點(diǎn)評(píng):本題考查了同學(xué)們對(duì)多項(xiàng)式的項(xiàng)的系數(shù)和次數(shù)定義的掌握情況.在處理此類題目時(shí),經(jīng)常用到以下知識(shí):
(1)單項(xiàng)式中的數(shù)字因數(shù)叫做這個(gè)單項(xiàng)式的系數(shù);
(2)一個(gè)單項(xiàng)式中,所有字母的指數(shù)和叫做這個(gè)單項(xiàng)式的次數(shù);
(3)幾個(gè)單項(xiàng)式的和叫多項(xiàng)式;
(4)多項(xiàng)式中的每個(gè)單項(xiàng)式叫做多項(xiàng)式的項(xiàng);
(5)多項(xiàng)式中不含字母的項(xiàng)叫常數(shù)項(xiàng);
(6)多項(xiàng)式里次數(shù)最高項(xiàng)的次數(shù),叫做這個(gè)多項(xiàng)式的次數(shù).