Expression 1: "f" left parenthesis, "x" , right parenthesis equals left brace, 0 less than "x" less than 1 : StartFraction, 1 Over StartRoot, "x" , EndRoot , EndFraction , "x" greater than or equal to 1 : StartFraction, 1 Over "x" squared , EndFraction , right bracefx=0<x<1:1x,x≥1:1x2
1
Expression 2: Start integral from 0 to infinity , end integral, "f" left parenthesis, "x" , right parenthesis "d" "x"∫∞0fxdx