2012 National Question 1 Single-choice Differentiating 2012_退役省自主命题 (2012·文) 1.复数( $2+i)^{2}$ 等于 A. $3+4 i$B. $5+4 i$C. $3+2 i$D. $5+2 i$ Answer keyA ☆ SaveCan't do it, show the explanation查看原卷 →