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## Studentc14 2 years ago functions: If f(x)=x^2-x+1, solve: 1) f(x+1) 2) f(-a) 3) 2f(x)-2 4) f(2x)

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1. Studentc14

CAN I post my answers and someone check it?

2. jaersyn

you mean "evaluate"?

3. Studentc14

probably, sorry

4. jaersyn

yeah, lol, just substitute whatever is in f(whatever is in here)

5. kmalone99

yes i'll check it

6. Studentc14

1) x^2+x+3 2) -a^2+a+1 (i didn't know if there was any way to simplify this? 3) 2x^2-x 4) 2x^2-2x+1

7. kmalone99

all wrong, it three right 2 f(x)-2?

8. Studentc14

its 2*f(x) -2

9. Studentc14

can you show me how to do them then?

10. kmalone99

yes

11. kmalone99

jaersyn i got this

12. jaersyn

all yours kmalone99

13. jaersyn

<_<

14. kmalone99

\[1) f(x+1)= (x+1)^{2}-(x+1)+1\] \[=(x+1)(x+1)-x-1+1\] \[=x ^{2}+2x+1-x=x ^{2}+x+1\]

15. Studentc14

Ok, I get #1. I just didn't distribute the negative sign.

16. kmalone99

2) f(-a)=\[f(-a)=(-a)^{2}-(-a)+1=a ^{2}+a+1\]

17. kmalone99

now retry 3 and 4

18. Studentc14

i got 2... i dont see what went wrong with 3 and i dont know how to simplify 4

19. Studentc14

wait- 3 should be 2x^2-2x?

20. kmalone99

great now on four you just did not square the 2

21. Studentc14

oh! so it would be 4x^2-2x+1 ?

22. kmalone99

yes great job you get A+

23. Studentc14

yay! lol I just always make silly simplifying mistakes or I miss a sign or something simple like that. Oh well, thanks very much ^_^

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