Topic Details (Notes format)

How to Find the Inverse of a 2x2 Matrix

Subject: Mathematics

Book: Maths Mastery

For a 2×2 matrix M=[[a, b],[c, d]], its inverse, if it exists, is (1/det(M))×[[d, –b],[–c, a]], where det(M)=ad–bc. For instance, if M=[[1,2],[3,4]], det(M)=1×4–2×3=4–6=–2. So M⁻¹= (1/–2)×[[4,–2],[–3,1]]= [[–2,1],[1.5,–0.5]]. Checking if det(M)≠0 ensures invertibility. The inverse helps solve AX=B by X=M⁻¹B, and is used in transformations, cryptography, or advanced robotics. Mastering 2×2 inverses sets a foundation for tackling higher-dimensional matrix inversions and linear algebra at large.

Practice Questions

The ratio of two numbers is 3:5, and their sum is 64. What are the numbers?

View Question

If a = 2 and b = 3, what is the value of (a^2 + b^2)?

View Question

A square is inscribed in a circle with a radius of 5 cm. What is the area of the square?

View Question

A train 150 m long passes a pole in 15 seconds. What is its speed?

View Question

If the ratio of two numbers is 3:5 and their HCF is 4, what are the numbers?

View Question

A number is increased by 20% and then decreased by 10%. What is the net change?

View Question

What is the HCF of 72 and 120?

View Question

If sin(θ) = 3/5 and θ is an acute angle, what is tan(θ)?

View Question

If the sides of a triangle are 6 cm, 8 cm, and 10 cm, what is the area of the triangle?

View Question

If x = 2 and y = 3, what is the value of (x^2 + y^2)?

View Question