math
posted by cal on .
I HAVE THESE ANSWERS FOR THE PROBLEMS. COULD YOU DOUBLE CHECK PLEASE, THIS IS A PRACTICE QUIZ WHICH ISN'T A GRADE IT JUST HELPS ME GET READY FOR THE TEST.
1) a
2) b
3) d
4) a
5) d
1. Solve x^3 + 6x^2 + 13x + 10 = 0.
a) –2 + 2i, –2 –2i, –2
b) 2 + i, 2 – i, –2
c) –2 + i, –2 – i, –2
d) 2 + 2i, 2 – 2i, –2
2. Find the discriminant and describe the nature of the roots of 3x^2 + 6x + 3 = 0.
a) The discriminant is 0 and there is/are one real root.
b) The discriminant is 4 and there is/are one real root.
c) The discriminant is 0 and there is no real root.
d) The discriminant is 7 and there is/are one real root.
3. Use the remainder theorem to find which of the following is not a factor of x^3 + 12x^2 + 47x + 60.
a) x + 5
b) x – 5
c) x + 4
d) x + 3
4. List all the rational roots of f(x) = 24x^3 – 10x^2 – 7x + 2.
a) 1/2, 1/4 ,2/3
b) 2/3,1/4 ,2/3
c) 1/2,1/3,1/2
d) 2/3,1/2,1/4
5. Use the rationalroot theorem to find the roots of 12x^3 – 8x^2 – 3x + 2 = 0.
a) 2/3,1/2,1/4
b) 2/3,1/2,1/2
c) 1/2,1/2,1/4
d) 2/3,1/3,1/3

The first two are wrong, I will check the others later.

3 is wrong, 4 is right, 5 is wrong