2 cos ⁡ ( x 2 − y 2 ) − 4 x 2 sin ⁡ ( x 2 − y 2 ) " 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;" > 2 cos ( x 2 − y 2 ) − 4 x 2 sin ( x 2 − y 2 ) 2cos⁡(x2−y2)−4x2sin⁡(x2−y2)

sin ⁡ ( x 2 − y 2 ) " 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;" > sin ( x 2 − y 2 ) sin⁡(x2−y2)

− 4 x 2 sin ( x 2 − y 2 )

− sin ⁡ ( x 2 − y 2 ) " 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;" > − sin ( x 2 − y 2 ) −sin⁡(x2−y2)