## help_needed 3 years ago Find the linearization L(x) of the function at a. f(x) = x^4 + 4x^2, a = −1

1. help_needed

I keep getting F(x) = f(x) = -12x - 8 as my asnwer but it's wrong :(

2. mukushla

is this right? \[L(x)=f(a)+(x-a)f'(a) \]

3. help_needed

yes

4. mukushla

5. mukushla

i think u got it from here :)

6. help_needed

yeah but thats exactly what i do but the asnwer sumhow is wrong

7. help_needed

f(-1) = 5 and f'(-1) = -12. So it becomes 5 + -12(x+1) = -12x + 8

8. help_needed

and it keeps marking it wrong

9. help_needed

idk what im doing wrong here

10. mukushla

lemme check

11. help_needed

srry that shud be -12x -8

12. mukushla

i got ... -12x-7

13. help_needed

WOWW IM SUCHHH A FAILLURE...OK wow i cant beleive i got the calc right and algebra wrong

14. help_needed

thank u lol i really cant beleive i got this wrong

15. mukushla

no problem ..it happens sometime :)

16. help_needed

ok but this one its not about the algebra. Im just cnfused how to do it. Do u mind helping if i post it

17. mukushla

ah sure :)

18. help_needed

Thanks im posting it as a dffnt question