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anemone
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The polynomial $x^3-kx+25$ has three real roots. Two of these root sum to 5. What is $|k|$?
Thanks I have done the needful in line for the flowtopsquark said:[sp]
There's a typo.
\(\displaystyle x^3 - k x + 25 = x^3 - 20 x + 25 \implies k = 20\), not -20.
[/sp]
-Dan
The degree of a polynomial is the highest exponent of the variable. In this case, the degree is 3 because the highest exponent of x is 3.
To find the value of k, we can use the rational root theorem or synthetic division to test different values of k until we find one that satisfies the equation. We can also use a graphing calculator to find the x-intercepts of the polynomial, which will give us the value of k.
Yes, the polynomial can have more than one value of k that satisfies the equation. This is because a polynomial can have multiple roots or solutions.
The value of k affects the graph of the polynomial by shifting it horizontally. If k is positive, the graph will shift to the right, and if k is negative, the graph will shift to the left. The value of k also affects the number of roots or solutions of the polynomial.
Finding the value of k allows us to fully understand the behavior and characteristics of the polynomial. It helps us determine the number of roots, the direction of the graph, and the behavior of the polynomial at certain points. This information is useful in solving real-world problems and making predictions based on the polynomial's behavior.