1. Which values are possible rational roots of 12x3+14x2−x+18=0 according to the rational root theorem?
Select each correct answer.
±1/9
±9/2
±1/4
±2/3
2. Which real numbers are zeros of the function?
f(x)=3x4−x3−27x2+9x
Select each correct answer.
-3
-1
-1/3
0
1/3
1
3
+129930 1. We take
All the possible factors of 18
_______________________ = ±9/2 , ±1/4 , ±2/3
All the possible factors of 12
2. f(x)=3x^4−x^3−27x^2+9x = 0
Write as 3x^4 - 27x^2 - x^3 + 9x = 0
Factors as
3x^2( x^2 - 9) - x(x^2 -9)
(x^2 - 9) (3x^2 -x)
( x+ 3) (x - 3) ( x ) (3x - 1)
The zeroes are -3, 0 , 1/3 and 3
