Whether you are preparing for a test or exam, or just to do your homework; you should always remember and know how to apply the following 25 important mathematics formulas that all high school students should know. We put them here in a simple list for you for easy reference. You may want to print this and attach it to your math workbook:

1. Pythagorean Theorem: a² + b² = c², used to find the missing side of a right triangle.
2. Quadratic Formula: x = (-b ± sqrt(b² – 4ac))/2a, used to find the roots of a quadratic equation.
3. Distance Formula: d = sqrt((x2 – x1)² + (y2 – y1)²), used to find the distance between two points in a coordinate plane.
4. Slope Formula: m = (y2 – y1)/(x2 – x1), used to find the slope of a line.
5. Midpoint Formula: ((x1 + x2)/2, (y1 + y2)/2), used to find the midpoint of a line segment.
6. Area of a Circle: A = πr², used to find the area of a circle.
7. Circumference of a Circle: C = 2πr or C = πd, used to find the circumference of a circle.
8. Volume of a Cylinder: V = πr²h, used to find the volume of a cylinder.
9. Volume of a Sphere: V = (4/3)πr³, used to find the volume of a sphere.
10. Surface Area of a Sphere: A = 4πr², used to find the surface area of a sphere.
11. Exponential Growth/Decay Formula: A = P(1 + r/n)^nt or A = P(1 – r/n)^nt, used to find the amount of money in an account or the population of a species after a certain amount of time.
12. Simple Interest Formula: I = Prt, used to find the amount of interest earned on a principal amount.
13. Compound Interest Formula: A = P(1 + r/n)^nt, used to find the amount of money in an account after a certain amount of time.
14. Perimeter of a Rectangle: P = 2l + 2w, used to find the perimeter of a rectangle.
15. Area of a Rectangle: A = lw, used to find the area of a rectangle.
16. Volume of a Rectangular Prism: V = lwh, used to find the volume of a rectangular prism.
17. Slope-Intercept Form: y = mx + b, used to find the equation of a line given the slope and y-intercept.
18. Point-Slope Form: y – y1 = m(x – x1), used to find the equation of a line given the slope and a point.
19. Mean: average of a set of numbers, calculated by adding all the numbers together and dividing by the total number of numbers.
20. Median: the middle number in a set of ordered numbers.
21. Mode: the number that appears most frequently in a set of numbers.
22. Standard Deviation: a measure of how spread out a set of numbers is from the mean.
23. Probability: the likelihood of an event occurring, calculated by dividing the number of favorable outcomes by the total number of possible outcomes.
24. Binomial Distribution: a probability distribution used to calculate the probability of a certain number of successes in a fixed number of trials.
25. Trigonometric Functions: sine, cosine, and tangent, used to find the ratios of sides in a right triangle.

These formulas can be used to solve a variety of problems in algebra, geometry, and statistics. High school students should be familiar with these formulas and know how to apply them to different types of problems.