What is this notation called?

[white canopy]

We briefly went over it in class and I can't find it in my notes. The class is discrete math

[river kelp]

matrix?

vectors?

i think its matrix

its able to be times out

[white canopy]

this is what its equal to

im just not sure how they got there

wait

nvm

[river kelp]

nah it cant be

matrix

[white canopy]

wait what is it?

[raven perch]

combimnation

[white canopy]

combination?

[raven perch]

or permutation

[river kelp]

oh ye choose

functins

[white canopy]

its combinations because it is dealing with sets not sequences. is there a specifi name for the notation they uesd though?

[raven perch]

A permutation is an ordered arrangement of r objects chosen from n objects.
A combination is a selection of r objects chosen from n objects and the order is not important.

[river kelp]

choose functions

[white canopy]

ah i see

so its just factoral over factoral

[river kelp]

on the calculator it should be the c symbol

[white canopy]

oh yeah i remember seeing this i feel dumb now

thank u lol

[river kelp]

,rotate

[white canopy]

top is = to n bottom is = to k

[river kelp]

yep

[white canopy]

thank you

[raven perch]

Yw

[light lake]

can u check my question?

should be very simple

[raven perch]

what is the topic?

[light lake]

I'll tag you

[river kelp]

https://discord.com/channels/268882317391429632/1278417727664422923