单选题
设y=
【正确答案】正确答案：y'=
．[sin(x
2
+3)]'=
．cos(x
2
+3)．(x
2
+3)' =2x
．[sin(x
2
+3)]'=
．cos(x
2
+3)．(x
2
+3)' =2x
【答案解析】
．[sin(x
2
+3)]'=
．cos(x
2
+3)．(x
2
+3)' =2x