Find the inverse of the general 2x2 matrix A= ([a, b],[c, d]) when does this inverse exist?

This is a typical further maths question, doing it correctly is a matter of carrying out a two-step process. 

Start by finding the determinant of the matrix,

det(A)=ad-bc

Then swap the entries a d and negate the other entries. After dividing by the determinant the inverse of A is given.

A^-1=1/(ad-bc)([d -b],[-c, a]).

LR

Related Further Mathematics A Level answers

All answers ▸

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) .


Solve the equation 2(Sinhx)^2 -5Coshx=5, giving your answer in terms of natural logarithm in simplest form


Using a Suitable substitution or otherwise, find the differential of y= arctan(sinxcosx), in terms of y and x.


Prove by induction that n^3+5n is divisible by 3 for every natural number.