anonymous one year ago Given the function f(x) = x2 and k = –3, which of the following represents a vertical shift?

1. anonymous

f(x) + k kf(x) f(x + k) f(kx)

2. SolomonZelman

when you are dealing with any function $$f(x)=x^w$$, a vertical shift is: $$f(x)=x^w+c$$ (shift up), OR $$f(x)+x^w-c$$ (shift down).

3. SolomonZelman

does this help, or not?

4. SolomonZelman

I mean $$fx)=x^w-c$$ for the last equation ...

5. SolomonZelman

btw, you don't need to know the value of the k to answer this question.

6. anonymous

yes this helps.

7. SolomonZelman

8. anonymous

would it be d?

9. SolomonZelman

I guess it didn't help at all....

10. SolomonZelman

it seems as though you are guessing....

11. anonymous

I'm trying to understand

12. anonymous

okay wait would it be a?

13. anonymous

im so bad at math sorry I'm really trying to get this

14. SolomonZelman

Say you have a function $$f(x)=x^w$$ -------------------------------- $$f(x\cdot k)=(x\cdot k)^w$$ that is just increasing the base, and gives you a different function. $$f(x)+c=x^w+c$$ ~ shift up when c>0 ~ shift down when c<0. $$kf(x)=k(x)^w$$ ~ you are stretching the function when k>1, ~ shrinking when 0<k<1, ~ reflecting the function across x axis and then shrinking it when -1<k<0, ~ reflecting the function across x axis and stretching it when k<-1. $$f(x+k)=(x+k)^w$$ ~ shift right when k<0 ~ shift left when k>0

15. anonymous

so it would be a

16. SolomonZelman

yes, A is the correct answer.

17. anonymous

thank you! it was right.

18. SolomonZelman

:)