Question

Solve x^4-x^3+2=0

Answer 1

solve for x

Answer 2

Is there a method specified that you have to use to obtain the answer?

Answer 3

nope

Answer 4

x^4 + x^3 + 2 = 0

y^2 + y + 2 = 0

Answer 5

Now you have the quadratic equation! :D

Answer 6

saifoo khan I don't get it. if y=x^2 then x^4 can be expressed as y^2, but we still have x^3 which does not work as smoothly. You can't use that method here. I'm not sure yet how to do this, I'll try to figure it out.

Answer 7

@A_Level_Student , which year question is this?

Answer 8

@Jire , now..?

Answer 9

y = x^3

x^4-x^3+2=0
y^2 - y + 2 = 0

Answer 10

all solutions or real solution only?

Answer 11

Sry guys i had a network problem so i was offline

Answer 12

@saifoo.khan i was from a textbook thanks.

Answer 13

@nikvist all solutions

Answer 14

uh saifoo khan'is wrong, just for the record. If y=x^3 then x^4-x^3+2=0 then x^3 in the former can definitely be expressed as y with the y=x^3 condition, but how does that help with the remaining x^4 in x^4-x^3-2=0 ._. well all that matters is that A_Level_Student got the right answer if he did tho.

Answer 15

@Jire , Yes you are correct. :D

Answer 16

Heh :D I wonder if he ever actually got the correct answer. If he tried to solve based on your substitution method by solving 0=y^2 + y + 2 = 0 and then squaring the answers, he got legitimate seeming answers which are incorrect though. A_Level_Student, please tell us are you sure of your answer so that you won't get the wrong idea of how to solve this. Although, I don't know how to do this other than with a calculator tho :S

Answer 17

\[x^4-x^3+2=0\quad\mbox{or}\quad x^4+x^3+2=0\quad\mbox{???}\]