已知函数f(x)满足f(a)+f(b)=f(ab),且f(2)=p,f(3)=q,则f(72)=
问题描述:
已知函数f(x)满足f(a)+f(b)=f(ab),且f(2)=p,f(3)=q,则f(72)=
答
f(9)=f(3*3)=2f(3)=2q
f(8)=f(2*4)=f(2)+2f(2)=3f(2)=3p
f(72)=f(9*8)=f(9)+f(8)=2q+3p