f(x)=−(x−4)(x−2)Which of the following is an equivalent form of the function f in which the maximum value of f appears as a constant or coefficient?Choose 1 answer:(A) f(x)=−x2+6x−8(B) f(x)=x2−6x+8(C) f(x)=−(x−3)2+1(D) f(x)=(x+3)2+1
Q. f(x)=−(x−4)(x−2)Which of the following is an equivalent form of the function f in which the maximum value of f appears as a constant or coefficient?Choose 1 answer:(A) f(x)=−x2+6x−8(B) f(x)=x2−6x+8(C) f(x)=−(x−3)2+1(D) f(x)=(x+3)2+1
Expand the given function: Expand the given function f(x)=−(x−4)(x−2) to find an equivalent form.f(x)=−(x2−2x−4x+8)f(x)=−(x2−6x+8)f(x)=−x2+6x−8This is the expanded form of the quadratic function.
Check the options: Check the given options to see which one matches the expanded form. Option (A) f(x)=−x2+6x−8 matches the expanded form we found in Step 1.
Determine the maximum value: Determine if the expanded form shows the maximum value as a constant or coefficient.The function f(x)=−x2+6x−8 is a downward-opening parabola, so the maximum value occurs at the vertex of the parabola.The vertex form of a parabola is f(x)=a(x−h)2+k, where (h,k) is the vertex of the parabola.To find the vertex, we can use the formula h=−2ab for a quadratic function ax2+bx+c.
Calculate the vertex: Calculate the vertex using the formula h=−2ab. For the function f(x)=−x2+6x−8, a=−1 and b=6. h=−2ab=−2∗(−1)6=−−26=3 Now we have the x-coordinate of the vertex, which is x=3.
Substitute x=3: Substitute x=3 into the function to find the y-coordinate of the vertex, which is the maximum value of f.f(3)=−(32)+6⋅3−8f(3)=−(9)+18−8f(3)=−9+18−8f(3)=9−8f(3)=1The vertex is at (3,1), so the maximum value of f is 1.
Write in vertex form: Write the function in vertex form using the vertex (3,1). f(x)=a(x−h)2+kf(x)=−(x−3)2+1This form shows the maximum value as a constant (1).
Match with options: Match the vertex form with the given options.Option (C) f(x)=−(x−3)2+1 matches the vertex form we found in Step 6.
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