fixes

src/main/kotlin/function/trigonometric/Cos.kt

@@ -0,0 +1,9 @@
+package function.trigonometric
+
+import function.base.ISin
+
+class Cos(private val sinImpl: ISin) : ICos {
+    override fun cos(x: Double, eps: Double): Double {
+        return sinImpl.sin(x + Math.PI / 2, eps)
+    }
+}