y = C 1 cos ⁡ x + C 2 sin ⁡ x − 2 x " role="presentation" style="display: inline-table; line-height: 0; font-size: 19.52px; overflow-wrap: normal; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; margin: 0px; padding: 1px 0px; color: rgb(0, 0, 0); font-family: "Microsoft YaHei"; position: relative;" > y = C 1 cos x + C 2 sin x − 2 x y=C1cos⁡x+C2sin⁡x−2x ;

y = C 1 cos ⁡ x + C 2 sin ⁡ x + 2 x " role="presentation" style="display: inline-table; line-height: 0; font-size: 19.52px; overflow-wrap: normal; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; margin: 0px; padding: 1px 0px; color: rgb(0, 0, 0); font-family: "Microsoft YaHei"; position: relative;" > y = C 1 cos x + C 2 sin x + 2 x y=C1cos⁡x+C2sin⁡x+2x ;

y = C 1 e x + C 2 e − x − 2 x " role="presentation" style="display: inline-table; line-height: 0; font-size: 19.52px; overflow-wrap: normal; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; margin: 0px; padding: 1px 0px; color: rgb(0, 0, 0); font-family: "Microsoft YaHei"; position: relative;" > y = C 1 e x + C 2 e − x − 2 x y=C1ex+C2e−x−2x ;

y = C 1 e x + C 2 e − x + 2 x " role="presentation" style="display: inline-table; line-height: 0; font-size: 19.52px; overflow-wrap: normal; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; margin: 0px; padding: 1px 0px; color: rgb(0, 0, 0); font-family: "Microsoft YaHei"; position: relative;" > y = C 1 e x + C 2 e − x + 2 x y=C1ex+C2e−x+2x .