div class=trans-pagebutton class=gotoPage data-page=1Page 1button div class=trans-imagea href=https:reader039fdocumentsnetreader039viewer20220216095e67547980f4c43ad93c7176html5page1jpg target=_blank img data-url=documenttanhu-sech2-u-dx-proof-d-tanh-u-a-dx-dx-dx-sinh-u-cosh-u-dx-dx-du-sinhu-dxhtmlpage=1 data-page=1 class=trans-thumb lazyload alt=Page 1: · tanhu = sech2 u dx Proof: d tanh u — dx dx dx Sinh u cosh u dx dx du sinhu dx du dx du du cosh u — sinhu dx cosh2 u du = sech2 u dx cosh2 u — sinh2 u dx cosh2 u cosh2 loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mM8Uw8AAh0BTZud3BwAAAAASUVORK5CYII= data-src=https:reader039fdocumentsnetreader039viewer20220216095e67547980f4c43ad93c7176html5thumbnails1jpg width=140 height=200 adivdivdiv class=trans-pagebutton class=gotoPage data-page=2Page 2button div class=trans-imagea href=https:reader039fdocumentsnetreader039viewer20220216095e67547980f4c43ad93c7176html5page2jpg target=_blank img data-url=documenttanhu-sech2-u-dx-proof-d-tanh-u-a-dx-dx-dx-sinh-u-cosh-u-dx-dx-du-sinhu-dxhtmlpage=2 data-page=2 class=trans-thumb lazyload alt=Page 2: · tanhu = sech2 u dx Proof: d tanh u — dx dx dx Sinh u cosh u dx dx du sinhu dx du dx du du cosh u — sinhu dx cosh2 u du = sech2 u dx cosh2 u — sinh2 u dx cosh2 u cosh2 loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mM8Uw8AAh0BTZud3BwAAAAASUVORK5CYII= data-src=https:reader039fdocumentsnetreader039viewer20220216095e67547980f4c43ad93c7176html5thumbnails2jpg width=140 height=200 adivdivdiv class=trans-pagebutton class=gotoPage data-page=3Page 3button div class=trans-imagea href=https:reader039fdocumentsnetreader039viewer20220216095e67547980f4c43ad93c7176html5page3jpg target=_blank img data-url=documenttanhu-sech2-u-dx-proof-d-tanh-u-a-dx-dx-dx-sinh-u-cosh-u-dx-dx-du-sinhu-dxhtmlpage=3 data-page=3 class=trans-thumb lazyload alt=Page 3: · tanhu = sech2 u dx Proof: d tanh u — dx dx...