經(jīng)濟(jì)數(shù)學(xué)基礎(chǔ)形成性考核冊答案

1、1電大經(jīng)濟(jì)數(shù)學(xué)基礎(chǔ)形成性考核冊及參考答案（一）填空題1..答案：0___________________sinlim0???xxxx2.設(shè)，在處連續(xù)，則.答案：1????????001)(2xkxxxf0?x________?k3.曲線在的切線方程是.答案：xy?)11(2121??xy4.設(shè)函數(shù)，則.答案：52)1(2????xxxf____________)(??xfx25.設(shè)，則.答案：xxxfsin)(?__________)2

2、π(???f2π?（二）單項選擇題1.函數(shù)的連續(xù)區(qū)間是（D）212????xxxyAB)1()1(?????)2()2(???????CD或)1()12()2(????????)2()2(???????)1()1(?????2.下列極限計算正確的是（B）A.B.1lim0??xxx1lim0???xxxC.D.11sinlim0??xxx1sinlim???xxx3.設(shè)，則（B）yx?lg2dy?ABCD12dxx1dxxln10ln1

3、0xxd1dxx4.若函數(shù)f(x)在點x0處可導(dǎo)，則(B)是錯誤的A函數(shù)f(x)在點x0處有定義B，但Axfxx??)(lim0)(0xfA?C函數(shù)f(x)在點x0處連續(xù)D函數(shù)f(x)在點x0處可微5.當(dāng)時，下列變量是無窮小量的是（C）.0?xABCDx2xxsin)1ln(x?xcos(三)解答題1計算極限（1）21123lim221??????xxxx3（6）4)2sin(4lim22????xxx原式=2)2sin(2lim2??

4、??xxxx==42)2sin(lim)2(lim22?????xxxxx2設(shè)函數(shù)，????????????0sin001sin)(xxxxaxbxxxf問：（1）當(dāng)為何值時，在處有極限存在？ba)(xf0?x（2）當(dāng)為何值時，在處連續(xù).ba)(xf0?x解：(1)1)(lim)(lim00??????xfbxfxx當(dāng)1f(0)f(x)lim10x?????有時，ba(2).1f(0)f(x)lim1ba0x?????有時，當(dāng)函數(shù)f(x