Question

prove that the equation has at least one real root. (b) Use your graphing device to find the root correct the three decimal places. x^5-x^2-4=0

Answer 1

please help me in the question made by me. Its my test tomorrow and I will fail if no one helps

Answer 2

@naouhmay Use Descartes' Rule of Signs to figure out the possible number of postive roots. Then, use the same rule to determine if there can be any negative real roots.

Answer 3

It says use the graphing advice. Therefore, simply put it into the graphing advice and that should give you an answer

Answer 4

For part a)
To me, you can do something like:
Let x =0, then f(0) = -4 (negative value)
Let x =2, then f(2) = 24 (positive value)
f(x) goes from negative to positive value in the interval [0,2], that shows it has at least one real root.

Answer 5

part b) allows you to use graphing device, then use it

Answer 6

http://www.wolframalpha.com/input/?i=x^5-x^2-4%3D0