Prove that f(x)= x+4 for x<=-2 -x for -2<x<2 x-4 for x=>2 is onto R, but not one-to-one. thanks

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Originally Posted by zhupolongjoe Prove that f(x)= x+4 for x<=-2 -x for -2<x<2 x-4 for x=>2 is onto R, but not one-to-one. thanks it is not 1-1 since f(-2) = f(6) and 6 is not equal to -2, obviously for onto, show that no matter what real number you pick, your funciton will map to it. do this piece by piece