Question

given f(x)=x^3+x+4 , find f^-1(1) accurate to 2 decimal places
the answer is f^-1(1)=-1.21
can anyone possibly guide me threw it?

Answer 1

set f(x) = 1, then solve for x

--> x^3 +x +3 = 0
try to factor out +-1 or +-3 using synthetic division

Answer 2

it's cant be factored

Answer 3

hmm there are no rational zeroes then ...use approximation methods
possible newtons method if you know calculus

what class is this for?

Answer 4

this is a preclac class

Answer 5

use graphing calculator :)

Answer 6

im trying that now

Answer 7

wolfram :)

Answer 8

http://www.wolframalpha.com/input/?i=x^3+%2Bx+%2B3+%3D0

Answer 9

sorry i don't know of any ways to do it by hand at a pre-calc level

Answer 10

no its ok . it proabaly does want me to use a calc

Answer 11

dam still confused

Answer 12

are u sure the equation above f(x)=x^3+.... not f(x)=x^2+...

Answer 13

yep

Answer 14

hmmm.. i give up :):)

Answer 15

how would i put the negative inverse in the graphing calc

Answer 16

lok this : (im scared after looking the answer :))
http://www.wolframalpha.com/input/?i=inverse+of+y%3Dx^3%2Bx%2B4

Answer 17

oh my

Answer 18

lmao

Answer 19

hahaha...

Answer 20

thanks man i appreciate you taking away your time to help me

Answer 21

you're welcome