The graph of y=f(x) is a parabola in the xy-plane that is symmetric with respect to the line x=−2. The y-coordinate of the vertex of the graph of f is a maximum function value. Which of the following equations could represent function f ?Choose 1 answer:(A) f(x)=5(x−2)2+3(B) f(x)=5(x+2)2+3(C) f(x)=−5(x−2)2+3(D) f(x)=−5(x+2)2+3
Q. The graph of y=f(x) is a parabola in the xy-plane that is symmetric with respect to the line x=−2. The y-coordinate of the vertex of the graph of f is a maximum function value. Which of the following equations could represent function f ?Choose 1 answer:(A) f(x)=5(x−2)2+3(B) f(x)=5(x+2)2+3(C) f(x)=−5(x−2)2+3(D) f(x)=−5(x+2)2+3
Identify Parabola Form: Identify the general form of a parabola with its vertex at the point (h,k). The general form of a parabola is given by y=a(x−h)2+k, where (h,k) is the vertex of the parabola. If the parabola opens upwards, a is positive, and if it opens downwards, a is negative. Since the y-coordinate of the vertex is a maximum, the parabola opens downwards, which means a should be negative.
Determine Symmetry Line: Determine the value of h from the symmetry line.The line of symmetry of the parabola is given by x=h. Since the parabola is symmetric with respect to the line x=−2, the value of h is −2.
Eliminate Incorrect Options: Eliminate the options that do not have the correct vertex form with h=−2.Option (A) f(x)=5(x−2)2+3 has h=2, which does not match the required line of symmetry x=−2.Option (B) f(x)=5(x+2)2+3 has h=−2, which matches the required line of symmetry.Option (C) f(x)=−5(x−2)2+3 has h=2, which does not match the required line of symmetry x=−2.Option (D) f(x)=−5(x+2)2+3 has h=−2, which matches the required line of symmetry.
Identify Parabola Direction: Identify the correct option based on the direction of the parabola.Since the y-coordinate of the vertex is a maximum, the parabola must open downwards, which means a should be negative. This eliminates option (B) because it has a positive a value.
Choose Correct Answer: Choose the correct answer from the remaining options.Option (D) f(x)=−5(x+2)2+3 is the only remaining option that satisfies both conditions: it has the correct line of symmetry (h=−2) and the correct direction of the parabola (a is negative).
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