Mathematics is a subject that often gives chills to the students, they estimate that the subject is difficult and do not try to understand it instead of creating and handling it as a problem. We understand that mathematics is a bit tricky subject, but it’s not completely a problem. The main problem is the strategy they use to prepare for the examination.
The problem is they do not try to understand the formulas instead go with the problems directly or even if they read them, they forget the formulas as they do not note them down in a particular place. Class 9 is crucial for students as the pattern and syllabus of the examination change suddenly and it also helps you clear your fundamentals for your class 10 board examination.
Best List of All the Formulas and The Equations for Class 9 Mathematics:
Geometry Formulas
This chapter is given as the area of parallelograms and triangles in your mathematics textbook. It shows how the amount of planer surface is covered with geometric figures.
Geometrical Shapes | Area (A) | Perimeter |
Rectangle | A = Length x Width | P = 2(Length + Width) |
Triangle | A = ½ x Breadth x Height | P = Sum of all the three sides of a triangle |
Trapezoid | A = ½ x Height x (b₁ x b₂) | P = Sum of all the sides of a trapezoid |
Parallelogram, | A = Breadth x Height | P = 2(a+ b)
Here. a = side B = base |
Circle | A = πr² | P = 2 πr |
Algebra Formulas
It is said that any equation in the form of ax + by + c = 0 where, a,b and c are real numbers and a and b are not zero it is known as a linear equation in two variables.
(x + β)² = x² + β² + 2 x β |
(x – β)² = x² + β² – 2 x β |
(x + θ) (x – θ) = x² – θ² |
(x + α)(x + θ) = x² + (α + θ)x + αθ |
(x + α)(x – θ) = x² + (α – θ)x – αθ |
(x – α)(x + θ) = x² + (θ – α)x – xθ |
(x – α)(x – θ) = x² – (α + θ)x + αq |
(α + θ)³ = α³ + θ³ + 3αθ(α + θ) |
(α – θ)³ = α³ + θ³ – 3αθ(α – θ) |
(α + β + θ)² = α² + β² + θ² + 2αβ + 2βθ + 2αθ |
(α + β – θ)² = α² + β² + θ² + 2αβ – 2βθ – 2αθ |
(α – β + θ)² = α² + β² + θ²- 2αβ – 2βθ + 2αθ |
(α – β – θ)² = α² + β² + θ² – 2αβ + 2βθ – 2αθ |
(x)³ + (β)³ = (x + β) (x² – xβ + β) |
(x)³ – (β)³ = (x + β) (x² – xβ + β) |
Check Out- NCERT Solutions for Class 9 Maths
Surface Area and Volume
It is classified as one of the most crucial chapters in class 9 mathematics. This chapter contains the calculation of two-dimensional figures and the space they’re taking.
Shape | Surface Area | Volume |
Cuboid | 2(lb + bh +lh)
l= length, b=breadth, h=height |
lbh |
Cube | 6a2 | a3 |
Cylinder | 2πr(h+r)
r = radius of circular bases h = height of cylinder |
πr2h |
Cone | πr(l+r)
r=radius of base l=slant height Also, l2=h2+r2, where h is the height of cone |
(1/3)πr2h |
Sphere | 4πr2 | (4/3)πr3 |
Heron’s Formula
A three-dimensional closed figure is known as a triangle. In this chapter, you’ll learn about the area and the perimeter of the triangle.
Area of the Triangle with 3 sides | √s(s-a)(s-b)(s-c)
Here, s = semi perimeter
a, b, and c are the sides of the triangle |
Semi Perimeter | S = (a + b + c)/2 |
Polynomial Formula
An expression comprises various coefficients and variables which do operations like addition, subtraction, multiplication and much more.
P (x) = anxn + an- 1xn- 1 – an- 2xn- 1 + …… ax + a0 |
Statistics Formulas
represent the data’s identification, collection, interpretation, analysis, and organization. It means to summarize the data in mathematical terms.
The measure of Central Tendency | |
Mean | Sum of Observation/Total number of observations = ∑ x/n |
Median | [(n+1)/2]th term [For an odd number of observations]
Mean of (n/2)th term and (n/2+1)th term [For even number of observations] |
Mode | The value which is repeated maximum time in a data set |
Probability Formula
It includes finding out the probability or possibility of an event, with the help of the expected outcome and all the trials and errors.
Empirical Probability = Number of trials with the expected outcome/Total number of Trials |
Useful Link- Important Questions for Class 9 Maths
FAQ
Q1. What is the list of all the chapters in class 9 mathematics?
Answer – Here’s the list of all the chapters of class 9 mathematics:
- Number System
- Polynomials
- Coordinate Geometry
- Linear Equation in Two Variables
- Euclid’s Geometry
- Lines and Angles
- Triangles
- Quadrilaterals
- Area of parallelogram and triangles
- Circles
- Constructions
- Heron’s Formula
- Surface, Area and Volume
- Statistics
- Probability
Also, Read– Benefits of Using NCERT Solutions for Board Examination!
Q2. How to remember all the formulas of class 9 mathematics?
Answer- You can remember all the formulas of class 9 mathematics by noting them down on a piece of paper and underlining the derivative of the formula, which will help you understand the foundation of the formula and where to use them.