Add array assertions for unary ops

Extend tests in tests/test_expr.py to verify elementwise behavior of unary functions with array inputs. Added assert all(...) checks for sqrt, exp, log, sin, and cos comparing results to numpy equivalents to ensure these functions handle array inputs correctly.

Author: Zeroto521

tests/test_expr.py

@@ -250,10 +250,15 @@ def test_unary(model):
     assert str(np.log([x, y])) == res
 
     assert sqrt(4) == np.sqrt(4)
+    assert all(sqrt([4, 4]) == np.sqrt([4, 4]))
     assert exp(3) == np.exp(3)
+    assert all(exp([3, 3]) == np.exp([3, 3]))
     assert log(5) == np.log(5)
+    assert all(log([5, 5]) == np.log([5, 5]))
     assert sin(1) == np.sin(1)
+    assert all(sin([1, 1]) == np.sin([1, 1]))
     assert cos(1) == np.cos(1)
+    assert all(cos([1, 1]) == np.cos([1, 1]))
 
 
 def test_mul():