Question
A function f : R® R satisfies f(x+y) = f(x) + f(y) for all x,y Î R and is continuous throughout the domain. If I1 + I2 + I3 + I4 + I5 = 450, where In = n.0òn f(x) dx. Find f(x).
Joshi sir comment
according to the given condition f(nx) = n f(x)
0òn f(x) dx
consider x = ny so this integration will become 0ò1 f(ny) ndy = n2 0ò1 f(y) dy = n2 0ò1 f(x) dx
now by using these conditions I1 = 13 0ò1 f(x) dx similarly others
put these values and get the answer