How many real roots does the equation (9x^5)-(4x^4)+(8x^3)-4x+1=0 have?

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SUMMARY

The polynomial equation (9x^5)-(4x^4)+(8x^3)-4x+1=0 has exactly three real roots. The derivative, calculated as (45x^4)-(16x^3)+(24x^2)-4, is essential for determining critical points. By applying the Intermediate Value Theorem, one can confirm the existence of roots between intervals where the function changes sign. Additionally, the presence of only one inflection point indicates that the polynomial cannot have more than three real roots.

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Homework Statement



Show that the equation (9x^5)-(4x^4)+(8x^3)-4x+1=0 has exactly 3 real roots.

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The Attempt at a Solution


I found a derivative of (45x^4)-(16x^3)+(24x^2)-4. I am not sure how to set this equal to zero
 
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Use the intermediate value theorem, if f(x) is a continuous function and there exist point a<b such that f(a)<0<f(b) or f(a)>0>f(b) then there is a point c, where f(c)=0.

My advice is to plot the graph and find approximatly where they are and then use the above to prove it so.
 
Also, you should show there's only one inflection point, so you have only 3 roots and not 5.
 

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