Question

16．在數(shù)軸上，如果點(diǎn)A所對(duì)應(yīng)的數(shù)為-$\sqrt{5}$，那么點(diǎn)A到原點(diǎn)的距離是$\sqrt{5}$．

Answer 1

分析 根據(jù)絕對(duì)值的定義可知，點(diǎn)A到原點(diǎn)的距離即為點(diǎn)A所對(duì)應(yīng)的數(shù)的絕對(duì)值，根據(jù)絕對(duì)值的意義求解即可．

解答 解：∵在數(shù)軸上，點(diǎn)A所對(duì)應(yīng)的數(shù)為-$\sqrt{5}$，
∴點(diǎn)A到原點(diǎn)的距離是|-$\sqrt{5}$|=$\sqrt{5}$．
故答案為$\sqrt{5}$．

點(diǎn)評(píng) 本題考查了實(shí)數(shù)與數(shù)軸，在數(shù)軸上，表示相反數(shù)的兩個(gè)點(diǎn)在原點(diǎn)的兩旁，并且兩點(diǎn)到原點(diǎn)的距離相等，實(shí)數(shù)a的絕對(duì)值就是在數(shù)軸上這個(gè)數(shù)對(duì)應(yīng)的點(diǎn)與原點(diǎn)的距離．