I wish I could count past 21...

[Sandy Buttcheeks]

Joy of joys. I am a week into my "summer school" maths, before I start my degree course proper in a few weeks, so I was just wondering...

When calculating an inverse matrix, is it one over the determinant then multiply a,b,c,d in your square matrix...or do you invert the matrix, negate the b,d component, then invert the a,d before multiplying by the determinants inverse? I know you guys are a wealth of knowledge in all things, so please excuse the asking.

Any help, gratefully received.

 

[Tarquin Thunderthighs lll]

The latter, but for the love of Thor, don't forget to take away the number you first thought of.

[Sandy Buttcheeks]

The latter, but for the love of Thor, don't forget to take away the number you first thought of.

I did...but then they started talking about imaginary numbers and real numbers. I thought I'd be real clever and tell them that one of my wrong answers was an imaginary answer...I've to bring my crayons tomorrow and keep quiet.   :'(