1:Show that the function f(x)=ln(x^{2 }+1) is one-to-one for x > 0 . Graphing does not count as proof. (Hint: Use the derivative of the function.)

2: Find a formula for the inverse function $f$^{-1 }(x) of $f$ (x)= 2x/x+1. Verify that $f$ ($f$ ^{-1}(3))= 3 and $f$ ^{-1}($f$ (5))=5

need help for the above 2 questions