def test_solves_equation(self):
"""
Make sure the returned function solves the equation correctly.
Solve 2 + 4x + 3x^2 where x is 5:
2 * 5^0 = 2
4 * 5^1 = 20
3 * 5^2 = 75
2 + 20 + 75 = 97
"""
poly_func = polynomial_function(2, 4, 3)
self.assertEqual(poly_func(5), 97)
val = 100 * (5 ** 0)
poly_func = polynomial_function(100)
self.assertEqual(poly_func(5), 100)
#2 + 3x
val = (2 * (5 ** 0)) + (3 * (5 ** 1))
poly_func = polynomial_function(2, 3)
self.assertEqual(poly_func(5), val)
#2 + 3x + 4x^2
val = (2 * (5 ** 0)) + (3 * (5 ** 1)) + (4 * (5 ** 2))
poly_func = polynomial_function(2, 3, 4)
self.assertEqual(poly_func(5), val)
def test_interface_contract(self):
# Make sure the function raises a TypeError when no coeffs are provided
self.assertRaises(TypeError, polynomial_function)
# The returned value must be callable
poly_func = polynomial_function(2, 4, 3)
self.assertTrue(callable(poly_func))
