Question the-fu

2.1 Nonlinear Functions - Function composition and evaluation
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The function f is defined by fx= x - 6 x - 2 x + 6 . In the xy-plane, the graph of y=gx is the result of translating the graph of y=fx up 4 units. What is the value of g0?

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The function f is defined by f x = x - 6 x - 2 x

Hard-difficulty · SAT Math · Nonlinear Functions — Function composition and evaluation. Read the question above, select your answer, and check the full explanation below to understand exactly why the correct choice works.

Answer explanation

The correct answer is 76 . It's given that the graph of y=gx is the result of translating the graph of y=fx up 4 units in the xy-plane. It follows that the graph of y=gx is the same as the graph of y=fx+4. Substituting gx for y in the equation y=fx+4 yields gx=fx+4. It's given that fx=x-6x-2x+6. Substituting x-6x-2x+6 for fx in the equation gx=fx+4 yields gx=x-6x-2x+6+4. Substituting 0 for x in this equation yields g0=0-60-20+6+4, or g0=76. Thus, the value of g0 is 76 .