  # Python | Numpy np.cheb2poly () method

NumPy | Python Methods and Functions

Using the `np.cheb2poly() ` method, we can get a polynomial from the Chebyshev series using ` np.cheb2poly () `.

Syntax: ` np.cheb2poly (array) `
Return: Return array having coefficients of polynomial.

Example # 1:
In this example we see that using ` np.cheb2poly () ` we can get polynomial from the Chebyshev series using this method.

 ` # NumPy import ` ` import ` ` numpy as np ` ` from ` ` numpy ` ` import ` ` polynomial as P `   ` x ` ` = np.array ([ 2 , 5 , 7 ]) ``   # using the np.cheb2poly () method `` gfg = P.Chebyshev (x) gfg = gfg.convert (kind = P.Polynomial) gfg = P.chebyshev.cheb2poly (gfg)   print (gfg) `

[Polynomial ([- 5., 5., 14.], domain = [- 1., 1.], window = [- 1., 1.])]

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Example # 2:

 ` # NumPy import ` ` import ` ` numpy as np ` ` from ` ` numpy ` ` import ` ` polynomial as P ` ` `  ` x ` ` = ` ` np .array ([` ` 2 ` `, ` ` 3 ` `, ` ` 5 ` `, ` ` 7 ` `, ` ` 11 ` `]) `   ` # using the np.cheb2poly () method ` gfg ` = ` ` P.Chebyshev (x) ` ` gfg ` ` = ` ` gfg.convert (kind ` ` = ` ` P.Polynomial) ` ` gfg ` ` = ` ` P.chebyshev.cheb2poly (gfg) `   ` print ` ` (gfg) `

[Polynomial ([8., -18., -78., 28., 88.], domain = [- 1., 1.], window = [- 1., 1.])]