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Showing 331–360 of 360 reference entries

Mathematics & logicArithmetic with fractions

Fraction arithmetic preserves value by using common denominators or reciprocals.

Method
Mathematics & logicAbsolute value and distance intervals

Absolute value measures distance from zero on the real line.

Definition
Mathematics & logicPercent and relative change

A percentage states a ratio per hundred and needs an explicit base.

Method
Mathematics & logicOrder rules for real inequalities

Scaling an inequality depends on the factor's sign.

Mathematical statement
Mathematics & logicInteger powers and positive-base rational powers

Negative exponents use reciprocals; rational exponents use principal roots.

Definition
Mathematics & logicReal logarithms and their laws

A logarithm is the inverse of exponentiation for an admissible positive base.

Definition
Mathematics & logicQuadratic formula and discriminant

The discriminant classifies the real solutions of a quadratic equation.

Mathematical statement
Mathematics & logicFunction composition and inverses

Composition feeds one output into another function; inversion requires unique preimages.

Definition
Mathematics & logicEuclidean triangle congruence tests

Specified matching sides and angles can establish the same triangle shape and size.

Mathematical statement
Mathematics & logicEuclidean triangle similarity tests

Triangle similarity keeps corresponding angles and one common positive side scale.

Mathematical statement
Mathematics & logicAcute-angle right-triangle ratios

Opposite and adjacent legs depend on the chosen acute angle.

Definition
Mathematics & logicRadian angle, circular arc and sector

Radian measure is arc length divided by radius.

Definition
Mathematics & logicPlane area and perimeter formulas

Area measures covered surface; perimeter measures boundary length.

Mathematical statement
Mathematics & logicRight-prism and cylinder volumes

Volume and surface area measure different aspects of a solid.

Mathematical statement
Mathematics & logicDescriptive sample center and spread

Mean, median, mode and sample variance summarize observed values.

Method
Mathematics & logicOrder of arithmetic operations

Grouping and equal-priority arithmetic evaluation.

Method
Mathematics & logicScientific notation

A normalized decimal coefficient with an integer power of ten.

Definition
Mathematics & logicDirect and inverse proportion

Constant-ratio and constant-product relationships.

Definition
Mathematics & logicAngles, intersecting lines and parallel lines

Euclidean line-angle relationships.

Mathematical statement
Mathematics & logicAngle sums of polygons

Interior and exterior angle sums for convex polygons.

Mathematical statement
Mathematics & logicSine and cosine rules for triangles

Side-angle laws beyond right triangles.

Mathematical statement
Mathematics & logicPigeonhole principle

A finite assignment forces a shared output when inputs outnumber outputs.

Mathematical statement
Mathematics & logicTotal probability and event Bayes' theorem

Finite-partition probabilities and reversal of event conditioning.

Mathematical statement
Mathematics & logicLeast common multiple

The smallest positive common multiple of positive integers.

Definition
Mathematics & logicPolynomials and degree

Finite sums of nonnegative integer powers with fixed coefficients.

Definition
Mathematics & logicDecimal rounding and significant digits

Decimal places, retained significant digits and rounding ties.

Method
Mathematics & logicCone and sphere volume and surface area

Euclidean cone and sphere mensuration.

Mathematical statement
Mathematics & logicCircle angles and tangents

Inscribed angles and radius-tangent perpendicularity.

Mathematical statement
Mathematics & logicStraight-line equations

Slope-intercept form of a nonvertical line.

Mathematical statement
Mathematics & logicPolygon perimeter and parallel-base areas

Boundary length and enclosed area measure different properties of a plane shape.

Method