[kurumi_00]

งั้นรบกวนช่วยดูให้ทีน่ะค่ะว่าถูกไหม

ขออนุญาตทำต่อเลยน่ะค่ะ

=$\frac{1}{2\sqrt{2}}[ln\sqrt{2}-1+ ln\sqrt{2}+1-(ln\sqrt{2}+1+ln\sqrt{2}-1)]$

=$\frac{1}{2\sqrt{2}}ln\frac{(\sqrt{2}-1)(\sqrt{2}+1)}{(\sqrt{2}+1)(\sqrt{2}-1)}$

= 0