def P3 (x) : return 3*x*x*x + 13. 6*x*x + 13.2*x + 47.8 Roots of polynomials can be found using function goalSeek if you supply the tested polynomial function as the function parameter, set the target parameter equal to zero, and start with a good LowLimit and HighLimit interval enclosing the root. Note that goalSeek requires that the tested function f is such that f(LowLimit) s target s f(HighLimit). All polynomials provided for this task will satisfy this requirement. For this test, you are provided with the file poly.txt containing coefficients of 25 polynomials. The first few lines of the file look as follows: # A B D Lo Hi Formula 3 -1. 8 -7.6 -20.8 -4.28 1 1. 88 3 x 3 - 1.8 x 2 - 7.6 x - 20.8 2 5 14 24 -6.57 0. 73 2 x 3 + 5 x 2 + 14 x + 24 2.7 7.59 9 . 49 3 . 85 -1. 86 5 . 85 2.7 x3 + 7.59 x^2 + 9.49 x + 3.85 1 - 8 - 32 0. 44 10.58 x 3 - 8 x - 32 . . . The first line is a header, you will have to skip it when reading the file. Each of the following lines starts with the four coefficients A, B, C, D, uniquely determining a polynomial Ax3 + Bx2 + Cx+D. The coefficients are followed by the suggested Lo and Hi limits. Each provided polynomial is guaranteed to have exactly one root in the interval Lo s x s Hi. We will use goalSeek to find this root for each of the provided polynomials. The last column is a conventional representation of a polynomial, which you can be pasted in WolframAlpha to confirm that your program correctly finds the roots. For example, here is the response for the first polynomial in the file, in particular it says that the real root is equal to 2.6. Task In this task, we are going to write a program test7.py that finds the roots of cubic polynomials listed in the file poly.txt using goalSeek function