Expert guides for parents, students and math enthusiasts. Algebra to Olympiads — we've got you covered.
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The goal was never to make kids faster at math — it was to make them fall in love with it. Speed is a byproduct of genuine understanding.

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Variables, equations, and the language of math
The objective function is the linear expression a linear programming problem sets out to maximize or minimize — usually written , where and are decision variables. This article defines it, shows the form, works six examples, and separates it clearly from the constraints.
The scalar triple product of three vectors is , a single number equal to the signed volume of the parallelepiped built on those vectors. This article covers the definition, the determinant formula, six worked examples, why a zero result means the vectors are coplanar, and the mistakes to avoid
The square root 1 to 25 chart gives through , where five values () are exact whole numbers and the other twenty are irrational, rounded here to three decimals. This article gives the full table, marks rational versus irrational, and shows how to read and rebuild it.
Shapes, proofs, and spatial thinking
Corresponding sides are sides in the same relative position in two figures that are either similar or congruent. In congruent figures corresponding sides are equal; in similar figures they are proportional - their ratio is constant. This article shows how to match them from vertex order, how to use the ratio to find a missing length, and the mistakes to avoid
A convex shape is a shape where the straight line joining any two points inside it stays completely inside - equivalently, every interior angle of a convex polygon is less than . This guide gives the one-line test, the properties, six worked examples, and the mistakes that make students misclassify a shape.
The four interior angles of a quadrilateral always add up to 360°, because any four-sided figure splits into two triangles of 180° each. This article shows why the rule holds, how to find a missing angle, the exterior-angle and cyclic-quadrilateral cases, and the mistakes to avoid.
Angles, waves, and circular harmony
The trigonometric ratios of specific angles are the exact values of sin, cos, tan, csc, sec, and cot at and — five angles whose ratios come out as clean surds, not decimals. This article gives the full values table, shows where each number comes from (the -- and -- triangles plus the unit circle), explains why entries like are undefined, and works through six examples.
Two angles are complementary when they add to , and the trigonometric ratio of an angle equals the co-ratio of its complement — so , , and . This article gives all six complementary-angle identities, proves them from a right triangle, explains why the "co-" in cosine means complement, and works through six examples — including the classic problem.
Trigonometric ratios in radians are the same six ratios — sin, cos, tan, csc, sec, cot — measured with the angle written in radians instead of degrees, where a full circle is radians rather than . This article gives the standard-angle table (), how to convert, why radians exist, six worked examples, and the mistakes that cost marks.
Raising confident, curious young mathematicians
Every essential formula, explained and derived
The maths formulas for class 10 span the full board syllabus — real numbers, polynomials, linear and quadratic equations, arithmetic progressions, triangles, coordinate geometry, trigonometry, circles, mensuration, statistics, and probability. This hub lists every formula by chapter, explains where each one comes from, and works one example per cluster so the formulas connect instead of floating loose.
The nPr formula counts how many ordered arrangements of objects you can make from distinct objects: . This article derives that formula from the counting principle, defines every symbol, shows where order makes a permutation different from a combination, and works six examples from a simple line-up to a locked-position arrangement.
The sum of arithmetic sequence formula adds the first terms of an arithmetic progression: . This article derives both forms by the pairing trick, defines every variable, works through six examples from one-step sums to finding from a known total, and clears up the mistakes that cost the most marks.
Crystal-clear definitions with worked examples
The CP formula recovers the cost price of an item from its selling price and a profit or loss: , , and from a percentage, or . This article derives all four forms, defines every term, and works six examples plus the percentage mistakes that flip answers.
The isosceles triangle formula set is: area (or from the equal side and base ), perimeter , and height . This article gives each formula, derives the height and area straight from the Pythagorean theorem, works six examples from one-step to a word problem, and clears up the mistakes that cost the most marks.
A chord is a straight line segment whose two endpoints both lie on a curve — most often a circle. This article defines the term, gives the chord-length formulas, lays out the key chord properties, works six examples, and clears up the chord-versus-diameter mix-up that trips students.
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