3fx=e+txe-e=e1+tx-e1-txet12x0fx=e1+tx-e1-txe1+x-e01+x2-ex20fx0fx0+12t101-t12t1-t1x=1t1hx=1+tx-e1-th0=0hx=1-tt1-t-e1-tx0x11-tLnt1-thx0hx011-tLnt1-thxh0=0fx0fxf0=0t12fx0+1937