Java Math sqrt()

sqrt() accepts a double value as an argument, and returns the correctly rounded positive square root of the argument. The return value is of type double.

Following is the syntax of sqrt() method.

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double value = sqrt(double x)

Since the definition of sqrt() function has double datatype as argument, you can pass int, float or long as arguments; because these datatypes could implicitly promote to double.

We shall learn about some of the special cases for sqrt() method with examples.

Example 1 – Math.sqrt(double)

In the following example, we use sqrt() method to find the square root of 10.

Java Program

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public class MathExample {
	public static void main(String[] args) {
		double x = 10;
		double sqrt_x = Math.sqrt(x);
		System.out.println(sqrt_x);
	}
}

Output

3.1622776601683795

Example 2 – Math.sqrt(int)

In the following example, we pass an int value for the argument to sqrt() method.

Java Program

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public class MathExample {
	public static void main(String[] args) {
		int x = 4;
		double sqrt_x = Math.sqrt(x);
		System.out.println(sqrt_x);
	}
}

Output

2.0

Similarly, you can provide a float or long value as argument to sqrt() method.

Example 3 – Math.sqrt(NaN)

In the following example, we pass Double.NaN as argument to sqrt() method. As per the definition of the sqrt() in Math class, the method should return NaN value.

Java Program

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public class MathExample {
	public static void main(String[] args) {
		double x = Double.NaN;
		double sqrt_x = Math.sqrt(x);
		System.out.println(sqrt_x);
	}
}

Output

NaN

Example 4 – Math.sqrt() – With Positive Infinity as Argument

In the following example, we pass Double.POSITIVE_INFINITY as argument to sqrt() method. As per the definition of the sqrt() method in Math class, the method should return positive infinity.

Java Program

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public class MathExample {
	public static void main(String[] args) {
		double x = Double.POSITIVE_INFINITY;
		double sqrt_x = Math.sqrt(x);
		System.out.println(sqrt_x);
	}
}

Output

Infinity

Example 5 – Math.sqrt() – With Negative Infinity as Argument

In the following example, we pass Double.POSITIVE_INFINITY as argument to sqrt() method. As per the definition of the sqrt() method in Math class, the method should return NaN for negative infinity as input value.

Java Program

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public class MathExample {
	public static void main(String[] args) {
		double x = Double.NEGATIVE_INFINITY;
		double sqrt_x = Math.sqrt(x);
		System.out.println(sqrt_x);
	}
}

Output

NaN

Conclusion

In this Java Tutorial, we learned about Java Math.sqrt() function, with example programs.