Prove that, can anyone help me, please?

cosh[ln(x+(x21)] = x

1 Answer
Dec 11, 2017

By definition:

coshx=ex+ex2

so:

coshln(x+x21)=12(eln(x+x21)+eln(x+x21))

coshln(x+x21)=12(x+x21+1x+x21)

coshln(x+x21)=12(x+x21)2+1x+x21

coshln(x+x21)=12(x2+2xx21+x21+1x+x21)

coshln(x+x21)=12(2x2+2xx21x+x21)

coshln(x+x21)=xx+x21x+x21

coshln(x+x21)=x