JavaScript 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.

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.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, multiply the random number by x + 1, then round down.

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.

Completed