diff --git a/src/main.rs b/src/main.rs
index 0e8ea5d..beac60f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -39,7 +39,7 @@ fn points_under_graph(
 fn get_sup(
     integral: &Integral<f64>
 ) -> f64 {
-    let multiplier = 1_000f64;
+    let multiplier = 1000.0;
     let b = &integral.bounds;
     let f = &integral.function;
     
@@ -49,8 +49,14 @@ fn get_sup(
         (((b.start * multiplier) as i64)..((b.end * multiplier) as i64))
             .map(|x| (x as f64) / multiplier)
     {
-        if f(i) > sup {
-            sup = f(i);
+        let y = f(i);
+        // dla aproksymacji π, f(-1) i f(1)
+        // dawały ∞, ten if naprawia problem
+        if sup.is_infinite() {
+            sup = y;
+        }
+        if y > sup && y.is_normal() {
+            sup = y;
         }
     }
     
@@ -129,33 +135,35 @@ fn graph_function(
 }
 
 fn main() {
+    // przykład z pdfu
     let i0 = Integral::<f64> {
         bounds: (1.0..3.0),
         function: Box::new(|x| x.powi(3)),
     };
-    graph_function("0.png", 50, &i0, 20.0);
+    graph_function("graphs/0.png", 50, &i0, 20.0);
 
     let i1 = Integral::<f64> {
         bounds: (0.0..8.0),
         function: Box::new(|x| x.powf(1.0 / 3.0)),
     };
-    graph_function("1.png", 50, &i1, 12.0);
+    graph_function("graphs/1.png", 50, &i1, 12.0);
 
     let i2 = Integral::<f64> {
         bounds: (0.0..std::f64::consts::PI),
         function: Box::new(|x| x.sin()),
     };
-    graph_function("2.png", 50, &i2, 2.0);
+    graph_function("graphs/2.png", 50, &i2, 2.0);
 
     let i3 = Integral::<f64> {
         bounds: (0.0..1.0),
         function: Box::new(|x| 4.0 * x * (1.0 - x).powi(3)),
     };
-    graph_function("3.png", 50, &i3, 0.2);
+    graph_function("graphs/3.png", 50, &i3, 0.2);
 
+    // aproksymacja π
     let i_pi = Integral::<f64> {
-        bounds: (0.0..1.0),
+        bounds: (-1.0..1.0),
         function: Box::new(|x| 1.0 / (1.0 - (x * x)).sqrt()),
     };
-    graph_function("pi.png", 50, &i_pi, std::f64::consts::PI / 2.0);
+    graph_function("graphs/π.png", 50, &i_pi, std::f64::consts::PI);
 }