Answer : B
Given the function f(x) = x^2 and k = –1
We plug in f(x) and k values and check
a. f(x) + k ----> \(x^2 -1\) , the value of 'a' is +1 . so it open upward
b. kf(x) ----> \(-1x^2\) , the value of 'a' is -1 . so it open downward
c. f(x + k)
----> \((x-1)^2\) , the value of 'a' is +1 . so it open upward
d. f(kx)----> \((-1x)^2=x^2\) , the value of 'a' is +1 . so it open upward
Option B is our final answer
