This is a complex function that has 3 pre-critical points aka x intercepts

My problem is when i get the remainder for the function i can't solve for the x intercept properly the remainder is 19 but what do i do with it ?

E.g (x^3+13x^2+39x+46)(x+ 9)


Answer = x^2 + 4x+3
(x+9) Root(x^3+13x^2+39x+46 )
-(x^3+9x^2)
=(4x^2+39x)
-(4x^2+36x)
=(3x+46)
-(3x+27)
= 19
Remainder 19.
Therefore (x2 + 4x+3)(x-9)+19
Further simplified (x+3)(x+1)(x-9)+ 19
Solve for x
y=(x+3)+19
0=(x+3)+19
x =?
graphed the function it does not give me the correct intercepts
can any one help ?

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Math!

Hahaha. I'm of no help to you...

Hmmm are you sure you factored and divided it right? cos you're taking the root of a cubic...

What is the answer supposed to be?

Going by the grapher here http://www.walterzorn.com/grapher/grapher_e.htm you're only supposed to have 2 roots

this is a special factoring method to factor more complex functions with its possible root and your supposed to have 3 roots

wait i could be wrong XD

not root sorry the root and division sign are almost eh same Lol iam just dividing the poly nomial

Why are you dividing by (x+9)?

Originally Posted by WavesSea

Therefore (x2 + 4x+3)(x-9)+19
Further simplified (x+3)(x+1)(x-9)+ 19
Solve for x
y=(x+3)+19
0=(x+3)+19
x =?
graphed the function it does not give me the correct intercepts
can any one help ?

err, your x should equal what is in the brackets in negatives.

ie,
x+3 = 0, then x = -3
x + 1 = 0, then x = -1
x - 9 = 0, then x = 9

and if you draw your graph using a graphing calculator, at your y = 19, you will have 3 distinct x intercepts.

this of course, is if i am reading your question correctly, and you didnt screw up the division. you cannot solve for x by simply removing 2 of the equations (x+1)(x-9), you have to solve with all of them together, or you change the question, and the reason you isolate the brackets is that if one of them equals 0, that section of the equation equals 0, giving you a x-intercept