Soru

Zorluk: OrtaFunction Notation and Transformations

The function ff is defined by f(x)=x2+6x1f(x) = -x^2 + 6x - 1. The function gg is defined by g(x)=f(x+2)5g(x) = f(x + 2) - 5. If the maximum value of g(x)g(x) in the xyxy-plane occurs at the point (h,k)(h, k), what is the value of h+kh + k?

Cevap: 4

Cevap

4
The vertex of the original quadratic function f(x)=x2+6x1f(x) = -x^2 + 6x - 1 is located at (3,8)(3, 8). The transformation g(x)=f(x+2)5g(x) = f(x + 2) - 5 translates the graph horizontally to the left by 22 units and vertically down by 55 units. This moves the vertex from (3,8)(3, 8) to (32,85)=(1,3)(3 - 2, 8 - 5) = (1, 3). Therefore, h=1h = 1 and k=3k = 3, and their sum h+kh + k equals 44.

Adım Adım Çözüm

1
Find the vertex of the function f(x)=x2+6x1f(x) = -x^2 + 6x - 1.
The vertex of f(x)f(x) is at (3,8)(3, 8).
By writing f(x)f(x) in vertex form, f(x)=(x3)2+8f(x) = -(x - 3)^2 + 8, we find that the maximum value of f(x)f(x) occurs at (3,8)(3, 8).
2
Determine the vertex (h,k)(h, k) of the transformed function g(x)=f(x+2)5g(x) = f(x + 2) - 5.
(h,k)=(1,3)(h, k) = (1, 3)
The horizontal shift of f(x+2)f(x + 2) translates the graph to the left by 22 units, changing the xx-coordinate from 33 to 32=13 - 2 = 1. The vertical shift of 5- 5 translates the graph down by 55 units, changing the yy-coordinate from 88 to 85=38 - 5 = 3.
3
Calculate the value of h+kh + k.
4
Adding the coordinates of the transformed vertex yields h+k=1+3=4h + k = 1 + 3 = 4.

Anahtar Kavram

Vertex form of a quadratic function and translation of functions.
Bu soruyu puanla