f(x)=−(x+1)(x+7)The function represents a parabola in the xy-plane. Which of the following is an equivalent form of f in which the y-intercept of the graph of f appears as a constant or coefficient?Choose 1 answer:(A) f(x)=−(x+4)2+9(B) f(x)=−(x+4)2−9(C) f(x)=−x2+8x+7(D) f(x)=−x2−8x−7
Q. f(x)=−(x+1)(x+7)The function represents a parabola in the xy-plane. Which of the following is an equivalent form of f in which the y-intercept of the graph of f appears as a constant or coefficient?Choose 1 answer:(A) f(x)=−(x+4)2+9(B) f(x)=−(x+4)2−9(C) f(x)=−x2+8x+7(D) f(x)=−x2−8x−7
Expand and Simplify: To find the y-intercept of the graph of f, we need to express f(x) in a form where x=0 yields the y-intercept directly. This means we need to expand the given product and simplify.Calculation: f(x)=−(x+1)(x+7)f(x)=−(x2+7x+x+7)f(x)=−(x2+8x+7)f(x)=−x2−8x−7
Check Options: Now, we check the options to see which one matches the expanded form of f(x) and has the y-intercept as a constant or coefficient.Option (A) f(x)=−(x+4)2+9 does not match because when expanded it would not yield −x2−8x−7.Option (B) f(x)=−(x+4)2−9 does not match for the same reason as (A).Option (C) f(x)=−x2+8x+7 is incorrect because the signs of the x terms are positive, not negative.Option (D) f(x)=−x2−8x−7 matches our expanded form and has the y-intercept (−7) as a constant.