With the help of cosine_transform() method, we can compute the cosine transformation and return the transformed function by using this method.

Syntax : cosine_transform(f, x, k, **hints)
Return : Return the transformed function.
Example #1 :
In this example we can see that by using cosine_transform() method, we are able to compute the cosine transformation and return the transformed function.
# import cosine_transform
from sympy import cosine_transform, exp, sqrt, cos
from sympy.abc import x, k, a
# Using cosine_transform() method
gfg = cosine_transform(exp(-a * x), x, k)
print(gfg)
Output :
sqrt(2)*a/(sqrt(pi)*(a**2 + k**2))
Example #2 :
# import cosine_transform
from sympy import cosine_transform, exp, sqrt, cos
from sympy.abc import x, k, a
# Using cosine_transform() method
gfg = cosine_transform(exp(-a * x), x, 5)
print(gfg)
Output :
sqrt(2)*a/(sqrt(pi)*(a**2 + 25))