How do you invert a 2x2 matrix?

Take a matrix A=(acbd), where a,b,c,d are numbers.

First find the determinant. This is ad-bc.

Now, rearrange the matrix to become (d-c-ba). Divide this by the determinant, to have A-1=1/(ad-bc)(d-c-ba). This is the inverse of A.

YP

Related Further Mathematics A Level answers

All answers ▸

The set of midpoints of the parallel chords of an ellipse with gradient, constant 'm', lie on a straight line: find its equation; equation of ellipse: x^2 + 4y^2 = 4


Find the general solution to the differential equation d^2x/dt^2 + 5 dx/dt + 6x = 4 e^-t


Convert the general complex number z=x+iy to modulus-argument form.


Find the equation of the tangent to the curve y = exp(x) at the point ( a, exp(a) ). Deduce the equation of the tangent to the curve which passes through the point (0,1) .