Java acos() Method
Java Number ClassThe acos() method is used to return the arccosine value of the specified double type parameter.
Syntax
double acos(double d)
Parameters
d -- any primitive data type, must be less than 1.
Return Value
Returns the arccosine value of the specified double type parameter. If the specified parameter is greater than 1, it returns NaN.
The return value is between 0 and Math.PI.
Example
The following example demonstrates the use of the acos() method:
Example
public class ExampleTest {
public static void main(String args[]){
double degrees = 45.0;
double radians = Math.toRadians(degrees);
System.out.format(The value of pi is %.4f%n, Math.PI);
System.out.format(The arccosine of %.4f is %.4f degrees %n, Math.cos(radians), Math.toDegrees(Math.acos(Math.sin(radians))));
}
}
public static void main(String args[]){
double degrees = 45.0;
double radians = Math.toRadians(degrees);
System.out.format(The value of pi is %.4f%n, Math.PI);
System.out.format(The arccosine of %.4f is %.4f degrees %n, Math.cos(radians), Math.toDegrees(Math.acos(Math.sin(radians))));
}
}
Compile the above program, the output result is:
pi 的值为 3.1416 0.7071 的反余弦值为 45.0000 度
Example
public class ExampleTest {
public static void main(String[] args) {
// Variables
double a = 0.5;
double b = 0.79;
double c = 0.0;
double d = 2;
// Output
System.out.println(Math.acos(a)); // 1.0471975511965979
System.out.println(Math.acos(b)); // 0.6599873293874984
System.out.println(Math.acos(c)); // 1.5707963267948966
System.out.println(Math.acos(d)); // d is greater than 1, so output NaN
}
}
public static void main(String[] args) {
// Variables
double a = 0.5;
double b = 0.79;
double c = 0.0;
double d = 2;
// Output
System.out.println(Math.acos(a)); // 1.0471975511965979
System.out.println(Math.acos(b)); // 0.6599873293874984
System.out.println(Math.acos(c)); // 1.5707963267948966
System.out.println(Math.acos(d)); // d is greater than 1, so output NaN
}
}
Compile the above program, the output result is:
1.0471975511965979 0.6599873293874984 1.5707963267948966 NaN
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