SOLUTION: How many complex roots does 5x6 + x4 3 = 0 have? (Points : 4) 3 4 5 6 Question 10. 10. How many rational roots does x4 + 3x2 + 2 = 0 ha

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: How many complex roots does 5x6 + x4 3 = 0 have? (Points : 4) 3 4 5 6 Question 10. 10. How many rational roots does x4 + 3x2 + 2 = 0 ha      Log On


   

Question 949232: How many complex roots does 5x6 + x4 3 = 0 have?
(Points : 4)
3
4
5
6

Question 10. 10. How many rational roots does x4 + 3x2 + 2 = 0 have?
(Points : 4)
0
1
2
4
Are these right
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
1)
How many complex roots does 5x%5E6+%2B+x%5E4+-3+=+0 have

Using Descartes rule of signs,if you have -3 there,then
Plugging in x=+%2B1, it has one+sign+change, so it has 1 positive real root.
Plugging in x=+-1, it also has one+sign+change, so it also has 1+negative real root.
Then, other four roots must be complex.
so, answer is: 4
3)
x%5E4+%2B+3x%5E2+%2B+2+=+0
it factors into %28x%5E2+%2B+1%29%28x%5E2+%2B+2%29 so it has all+complex roots
answer is: 0 rational roots