initial

1sem/programming basics/z5/13.cpp

@@ -0,0 +1,20 @@
+// pb_z5_13.cpp
+// Горбацевич Андрей
+#include <iostream>
+using namespace std;
+
+double ai(int);
+
+int main() {
+    int N;
+    cout << "N >>>";
+    cin >> N;
+    cout << "S= " << ai(N);
+}
+
+double ai(int N) {
+    double out = 0;
+    for (int i = 1; i <= N; i++)
+        out += (float)i/((float)i+1.f);
+    return out;
+}

1sem/programming basics/z5/14.cpp

@@ -0,0 +1,28 @@
+// pb_z5_14.cpp
+// Горбацевич Андрей
+#include <iostream>
+using namespace std;
+
+double ai(int, double);
+double spow(double, double);
+
+int main() {
+    int N;
+    double x;
+    cout << "N, x >>>";
+    cin >> N >> x;
+    cout << "P= " << ai(N, x);
+}
+
+double ai(int N, double x) {
+    double out = 1;
+    for (int i = 1; i <= N; i++)
+        out *= 2 * spow(x, i);
+    return out;
+}
+
+double spow(double f, double p) {
+    double out = 1;
+    for (int i = 0; i < p; i++) out *= f;
+    return out;
+}

1sem/programming basics/z5/15.cpp

@@ -0,0 +1,25 @@
+// pb_z5_15.cpp
+// Горбацевич Андрей
+#include <iostream>
+using namespace std;
+
+double ai(int);
+double s(int);
+
+int main() {
+    int N;
+    cout << "N >>>";
+    cin >> N;
+    cout << "S= " << ai(N);
+}
+
+double ai(int N) {
+    double out = 0;
+    for (int i = 1; i <= N; i++)
+        out += i * s(i);
+    return out;
+}
+
+double s(int i) {
+    return (i % 2? -1 : 1);
+}