f(x)+f(x+1/2) =1f(x)=1-f(x+1/2)0∫2f(x)dx=0∫21-f(x+1/2)dx0∫2f(x)dx=2-0∫2f(x+1/2)dxtake (x+1/2)=vdx=dv0∫2f(v)dv=2-0∫2f(v)dv2(0∫2f(v)dv)=20∫2f(v)dv=10∫2f(x)dx=1