We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.
 
+0  
 
0
172
1
avatar+472 

How Many Complex roots does the polynomial equation have?

3x^5-2x+1=0

 

 

A. 2

 

B. 3

 

C. 4

 

D. 5

 Oct 2, 2018
 #1
avatar+101857 
+1

3x^5  - 2x  + 1    =   0 

 

-1 is a root because   3(-1)^5  - 2(-1) + 1   =  -3 + 2 + 1  = 0

 

Look at the graph here : https://www.desmos.com/calculator/3lxzwfyib2

 

The graph never  intersects the  x axis again...so the remaining roots are complex

 

WolframAlpha shows that the polynomial has 4  remaining complex roots : 

 

https://www.wolframalpha.com/input/?i=3x%5E5%C2%A0+-+2x%C2%A0+%2B+1%C2%A0+%C2%A0+%3D%C2%A0+%C2%A00

 

 

cool cool cool

 Oct 2, 2018

8 Online Users

avatar
avatar
avatar