diff --git a/src/main.rs b/src/main.rs
index 64abc33..7f8fe9c 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -146,10 +146,16 @@ impl Derive for Op {
             ),
             Self::Add(a, b) => Op::Add(a.derive(), b.derive()),
             Self::Sub(a, b) => Op::Sub(a.derive(), b.derive()),
-            Self::Pow(a, b) => Op::Pow(
-                Op::Mul(a.clone(), b.clone()).into(),
-                Op::Sub(b.clone(), Value::Const(1.0)).into(),
-            ), 
+            Self::Pow(a, b) => match b {
+                Value::Eval(e) => Op::Mul(
+                    unimplemented!("Ln(x)"),
+                    Op::Pow(a.clone(), b.clone()).into(),
+                ),
+                b => Op::Pow(
+                    Op::Mul(a.clone(), b.clone()).into(),
+                    Op::Sub(b.clone(), Value::Const(1.0)).into(),
+                ),
+            },
         }
         .into()
     }
@@ -206,6 +212,11 @@ fn main() {
         Value::Const(9.0),
     )
     .into();
-    let res = n_root(9.0, 2.0);
+    fn pow_to_x(b: f64) -> Value {
+        Op::Pow(Value::Const(b), Var::val("x")).into()
+    }
+    let eq: Value = Op::Sub(Op::Add(pow_to_x(4.0), pow_to_x(6.0)).into(), pow_to_x(9.0)).into();
+    //let res = n_root(9.0, 2.0);
+    let res = newton_raphson(&eq, 1.0).last();
     println!("1.0 - {}/{} ==> {}", &eq, eq.derive(), res.unwrap());
 }