• 2022-05-29
    已知 [tex=8.714x1.5]+1iKUCoDx6AKsW9Bcfgpwn7361hAcYgBADDwi3buZeQ=[/tex][tex=3.071x1.0]G1CdFBL3ASSwSc44W+C3FQ==[/tex]的等高线是什么图形?它各点的斜率是多少?