Given that the function y = f (x) defined on the real number set R is symmetric with respect to the straight line x = 2, and the analytic expression of X ∈ [0,2] is y = 2x-1, then the analytic expression of F (x) on X ∈ [2,4] is y = 2x-1____ .

Given that the function y = f (x) defined on the real number set R is symmetric with respect to the straight line x = 2, and the analytic expression of X ∈ [0,2] is y = 2x-1, then the analytic expression of F (x) on X ∈ [2,4] is y = 2x-1____ .

F (x) is symmetric with respect to x = 2, so f (x) = f (4-x)
If 2 ≤ x ≤ 4, then 0 ≤ 4-x ≤ 2
f(x)=f(4-x)=2(4-x)-1=7-2x