SOLUTION: If f(x)=x(x-1)(x-4)^2, use interval notation to give all values of x where f(x)>0. My answer is (-infty,0) u (1,4) u (4,infty) is this right. thanks again.

Algebra ->  Points-lines-and-rays -> SOLUTION: If f(x)=x(x-1)(x-4)^2, use interval notation to give all values of x where f(x)>0. My answer is (-infty,0) u (1,4) u (4,infty) is this right. thanks again.      Log On


   



Question 43596This question is from textbook Algebra and trigonometry with analytic geometry
: If f(x)=x(x-1)(x-4)^2, use interval notation to give all values of x where f(x)>0. My answer is (-infty,0) u (1,4) u (4,infty) is this right. thanks again. This question is from textbook Algebra and trigonometry with analytic geometry

Found 2 solutions by psbhowmick, Nate:
Answer by psbhowmick(878) About Me  (Show Source):
You can put this solution on YOUR website!
So you are right!

f%28x%29=x%28x-1%29%28x-4%29%5E2
For all real values of 'x', %28x-4%29%5E2+%3E+0 except when x = 4.
So, for f(x) to be greater than 0, x%28x-1%29%3E0.
This is possible if

1) Case I
both x > 0 and (x - 1) > 0 which implies x > 1 [as x > 1 automatically satisfy both the conditions]

2) Case II
both x < 0 and (x - 1) < 0 which implies x < 0 [as x < 0 automatically satisfy both the conditions]

So for f(x) > 0, either x > 1 [from Case I] or x < 0 [from Case II]; also x not equal to 4.
Hence, the answer is (-infinity,0)U(1,4)U(4,infinity).

Answer by Nate(3500) About Me  (Show Source):
You can put this solution on YOUR website!

All the values above the x-axis are your answers because f%28x%29 is greater than zero.
Answer:
x+%3C+0
1+%3C+x+%3C+4
x+%3E+4