Retake Unit 2 Flashcard 3 Part A IGCSE

Front

What is the formula for the area of a rectangle?

Back

Area = length × width.

Front

If the length of a rectangle is seven less than twice the width, how can this be expressed algebraically?

Back

Length = 2(width) - 7.

Front

What is the quadratic formula used to solve equations of the form ax² + bx + c = 0?

Back

x = (-b ± √(b² - 4ac)) / (2a).

Front

What does it mean to simplify an irrational solution?

Back

To express the solution in its simplest form, removing any unnecessary radicals.

Front

How do you find the roots of a quadratic equation?

Back

By using factoring, completing the square, or applying the quadratic formula.

Front

What are consecutive integers?

Back

Integers that follow each other in order, such as n and n+1.

Front

What is the relationship between the square of an integer and its multiples?

Back

The square of an integer can be expressed as a multiple of that integer.

Front

How do you solve for x in the equation (2/3)x² + 15 = 23?

Back

First, isolate x²: (2/3)x² = 8, then multiply by (3/2) to find x² = 12, leading to x = ±2√3.

Front

What is the significance of the discriminant in a quadratic equation?

Back

The discriminant (b² - 4ac) determines the nature of the roots: two real, one real, or two complex.

Front

How can you express the area of a rectangle if its dimensions are given in terms of a variable?

Back

Area = (2x - 7) * x, where x is the width.