Question

设函数f(x)=ax+b,且f(1)=5/2,f(2)=4,则f(4)等于几?

Answer 1

函数f(x)=ax+b,且f(1)=5/2,f(2)=4

所以 A+B=5/2 ········1

2A+B=4 ········2

1-2 得 A=3/2

B=1

所以f(x)=3/2x+1

即f(4)=7