Hello, everyone! I want to introduce my best friend to you. My best friend is Lucy. She is from America. She is 13 years old. Her birthday is on June 6th. We are in the same class. At school she likes English best. She can speak it
函数y=lnx+1-x2-3x+4的定义域为( )
《剑桥中华人民共和国史》主编英国学者麦克法夸尔说:“ 1949是政权的更替,1979年才是中国真正意义上的解放。从这个意义上讲,邓小平在中国历史上的地位比***高。”作者的观点主要是立足于( )
①ax2+bx+c=0;②2x(x﹣3)=2x2+1;③x2=4;④(2x)2=(x﹣1)2⑤ x2−3xx =2x2.