How do you find the determinant of a matrix?

Finding the matrix of a matrix can be done in 5 steps. Step 1 involves finding the determinant of the matrix, and putting this value aside for later. Step 2 finds the cofactors of each element. The cofactor of an element 'a' is the determinant of the matrix created by removing the row and column that contain the element 'a' from the original matrix. For step 3 we need to replace each element with its cofactor. For a 2 by 2 matrix, step 2 and 3 essentially swaps each element with its diagonal. Now, for the 4th step we transpose the matrix, which is basically making the rows into columns. This is like reflecting the matrix along its leading diagonal. For the last step, we multiply this result by 1 over the determinant that we calculated in step 1, and we have our matrix inverse!

LC
Answered by Lizzie C. Further Mathematics tutor

4004 Views

See similar Further Mathematics A Level tutors

Related Further Mathematics A Level answers

All answers ▸

If the complex number z = 5 + 4i, work out 1/z.


A golf ball is hit from horizontal ground with speed 10 m/s at an angle of p degrees above the horizontal. The greatest height the golf ball reached above ground level is 1.22m. Model the golf ball as a particle and ignore air resistance. Find p.


A particle is moving in a straight line with simple harmonic motion. The period of the motion is (3pi/5)seconds and the amplitude is 0.4metres. Calculate the maximum speed of the particle.


Let A, B and C be nxn matrices such that A=BC-CB. Show that the trace of A (denoted Tr(A)) is 0, where the trace of an nxn matrix is defined as the sum of the entries along the leading diagonal.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning