SOLUTION: Find the least value of the polynomial p(x) = x^4 - 4x^3 + 6x^2 - 4x + 6.

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Find the least value of the polynomial p(x) = x^4 - 4x^3 + 6x^2 - 4x + 6.      Log On


   



Question 254427: Find the least value of the polynomial p(x) = x^4 - 4x^3 + 6x^2 - 4x + 6.
Found 2 solutions by Theo, Alan3354:
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
I couldn't find any formulas that would let you find the minimum of that equation.

I graphed it instead and saw that the minimum point looks like it is at x = 1.

graph%28600%2C600%2C-5%2C5%2C-1%2C8%2Cx%5E4+-+4%2Ax%5E3+%2B+6%2Ax%5E2+-+4%2Ax+%2B+6%29

I took 2 points before and after 1 to test this out.

I chose x = .8 and x = 1.2

at x = .8, y = 5.0016

at x = 1.2, y = 5.0016

this kind of confirms that the axis of symmetry is at x = 1.

you can try other points like .9 and 1.1, and .7 and 1.3.

I suspect the minimum point is at x = 1.

I checked out a website that talked about minimum and maximum points of a polynomial, but I couldn't find anything in there that showed how it could be done other than graphically.

click here for that.

http://www.algebralab.org/lessons/lesson.aspx?file=Algebra_poly_maxmin.xml




at x = 1.2, y =

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Find the least value of the polynomial p(x) = x^4 - 4x^3 + 6x^2 - 4x + 6
p'(x) = 4x^3 - 12x^2 + 12x - 4
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Using graphs, or Excel or trial and error, the p' has only one zero, at x = 1
--> the minimum of p(x) is at x = 1, and is p(1) = 5.