public void FindNthRoot_InvalidValues_ThrowArgumentException()
 {
     Assert.Throws <ArgumentException>(() => NewtonImplementation.FindNthRoot(-0.01, 2, 0.0001));
     Assert.Throws <ArgumentException>(() => NewtonImplementation.FindNthRoot(0.001, -2, 0.0001));
     Assert.Throws <ArgumentException>(() => NewtonImplementation.FindNthRoot(0.01, 2, -0.0001));
 }
 public double FindNthRootTests(double number, int grade, double accurancy)
 => NewtonImplementation.FindNthRoot(number, grade, accurancy);