With the help of sympy.Derivative() method, we can create an unevaluated derivative of a SymPy expression. It has the same syntax as diff() method. To evaluate an unevaluated derivative, use the doit() method.
Syntax: Derivative(expression, reference variable) Parameters: expression – A SymPy expression whose unevaluated derivative is found. reference variable – Variable with respect to which derivative is found. Returns: Returns an unevaluated derivative of the given expression.
Example #1:
# import sympy from sympy import *
x, y = symbols( 'x y' )
expr = x * * 2 + 2 * y + y * * 3
print ( "Expression : {}" . format (expr))
# Use sympy.Derivative() method expr_diff = Derivative(expr, x)
print ( "Derivative of expression with respect to x : {}" . format (expr_diff))
print ( "Value of the derivative : {}" . format (expr_diff.doit()))
|
Output:
Expression : x**2 + y**3 + 2*y Derivative of expression with respect to x : Derivative(x**2 + y**3 + 2*y, x) Value of the derivative : 2*x
Example #2:
# import sympy from sympy import *
x, y = symbols( 'x y' )
expr = y * * 2 * x * * 2 + 2 * y * x + x * * 3 * y * * 3
print ( "Expression : {}" . format (expr))
# Use sympy.Derivative() method expr_diff = Derivative(expr, x, y)
print ( "Derivative of expression with respect to x : {}" . format (expr_diff))
print ( "Value of the derivative : {} " . format (expr_diff.doit()))
|
Output:
Expression : x**3*y**3 + x**2*y**2 + 2*x*y Derivative of expression with respect to x : Derivative(x**3*y**3 + x**2*y**2 + 2*x*y, x, y) Value of the derivative : 9*x**2*y**2 + 4*x*y + 2
Example #3:
# import sympy from sympy import *
# Derivative method for trigonometric functions x, y = symbols( 'x' )
expr = sin(x) + cos(x)
print ( "Expression : {}" . format (expr))
# Use sympy.Derivative() method expr_diff = Derivative(expr, x)
print ( "Derivative of expression with respect to x : {}" . format (expr_diff))
print ( "Value of the derivative : {}" . format (expr_diff.doit()))
|
Output:
Expression : sin(x) + cos(x)
Derivative of expression with respect to x : Derivative(sin(x) + cos(x), x)
Value of the derivative : -sin(x) + cos(x)