Let the functionf(x)=3x2−4x+8log1+x be defined on the interval [0, 1]. The even extension of f(x) of the interval [-1, 1] is

f(x)=−f(x)      x∈[0,1]          −f(−x)    x∈[−1,0]f(x)=3x2−4x+8log1+xx∈[0,1]f(x)=3x2+4x+8log1+xx∈[−1,0]∴f(x)=3x2−4x+8log1+xx∈[−1,1]