Java Math
Basic Math operators:
3 + 2 // Addition
3 - 2 // Subtraction
3 * 2 // Multiplication
3 / 2 // Division
3 % 2 // Modulus (remainder after division)
Math.sqrt(4) // Square root
Math.pow(4,3) // Exponent (e.g. 4 to the power of 3)
- Spaces between numbers and math symbols are optional
- The result of Math.pow and Math.sqrt are stored as data type 'double', you may need to use variable casting if working with other data types
Rounding:
Math.round(3.123) // Rounds to the nearest whole number (e.g. 3)
Math.floor(3.123) // Rounds down (e.g. 3)
Math.ceil(3.123) // Rounds up (e.g. 4)
Trigonometry:
Math.PI // Pi: 3.14159...
Math.toRadians(90) // Converts from degrees to radians, (e.g. 1.571)
Math.toDegrees(Math.PI/2) // Converts from radians to degrees, (e.g. 90)
Math.sin(Math.PI/4) // Calculates the sine of an angle in radians (e.g. 0.707)
Math.cos(Math.PI/4) // Cosine
Math.tan(Math.PI/4) // Tangent
Math.asin(1/2) // Calculates the arc sine, giving the angle in radians (e.g. 0.524)
Math.acos(1/2) // Arc cosine
Math.atan(1/2) // Arc tangent
Math.hypot(1,2) // Calculates hypotenuse length, given length of other legs of right triangle
- It's easiest to work with radians consistently in the code, then convert it to degrees right before displaying it to the user if needed
Logarithms:
Math.E // Euler's number, e: 2.718...
Math.log(Math.E) // Natural log (e.g. 1)
Math.log10(100) // Log base 10 (e.g. 2)
Other:
Math.max(209,123) // Gets the greatest of two numbers (e.g. 209)
Math.min(209,123) // Gets the least of two numbers (e.g. 123)
Math.random() // Generates a random number between 0 and 1, including 0
- To generate a random number between 0 and some number x, just multiply the random number by x + 1, then round down (or cast it to an int) if needed
Challenge
Write code that will display the square root of the fraction of 11 divided by pi, but don't use any number besides 1 in the code.
Quiz
Completed