Maharashtra Board Class 9 Mathematics — Flashcards for Quick Revision

A: A set is a collection of objects where we can definitely and clearly decide which objects belong to it. The objects in a set are called elements or members. Example: A = {1, 2, 3, 4, 5} is a set of fi

A: 1. Listing Method (Roster Method): Write all elements inside curly brackets, separated by commas. Example: A = {2, 4, 6, 8} 2. Rule Method (Set Builder Form): Use a variable with a condition. Example:

A: A Singleton Set is a set that contains exactly one element. Example: A = {5} or B = {x | x is an even prime number} = {2}. These sets have only one member each.

A: Point, Line, and Plane are the three basic undefined terms in geometry. These are fundamental concepts that we do not define but use to build all other geometric concepts. Lines and planes are sets of

A: The distance between points D and E is 2 units. Distance = larger coordinate - smaller coordinate = 3 - 1 = 2. This is written as d(D,E) = 2 or l(DE) = 2.

A: To find distance between two points: 1) Identify their coordinates, 2) Subtract the smaller coordinate from the larger coordinate. The result is always positive. For example: if A is at -5 and B is at

A: A rational number is any number that can be expressed in the form p/q, where p and q are integers and q ≠ 0. Examples: 3/4, -7/5, 0.25. Set notation: Q = {p/q | p, q ∈ I, q ≠ 0}

A: 1. Terminating decimals (e.g., 2/5 = 0.4, 7/8 = 0.875) 2. Non-terminating recurring decimals (e.g., 1/3 = 0.333..., 22/7 = 3.142857142857...) Note: The bar notation is used for recurring decimals like

A: 1. Commutative: a + b = b + a (e.g., 2/3 + 1/4 = 1/4 + 2/3) 2. Associative: (a + b) + c = a + (b + c) 3. Identity: a + 0 = 0 + a = a (0 is additive identity) 4. Inverse: a + (-a) = 0 (-a is additive i