8/23/2014
If f(x) = 3x2 + 4x + 5, what must the value of k be so that the graph of f(x – k) is symmetric about the y-axis?
a) -4  b) -4/3  c) -2/3  d) 2/3  e) 4/3



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8/23/2014 Solution. D. Upon completing the square, f(x) = 3(x + 2/3)2 + 11/3, with the Axis of Symmetry being x = -2/3 so that f(x – 2/3) would shift it 2/3 units to the right and make it symmetric about the y-axis, so k = -2/3.