Dot product Memes

Linear algebra students everywhere are triggered by this classic mathematical troll move. The equation shows y = (y·u₁/u₁·u₁)u₁ + (y·u₂/u₂·u₂)u₂ where those fractions are screaming to be simplified. But textbook authors refuse to cancel the u's because they're not actually the same term - one is a dot product in the numerator and another is in the denominator. It's like thinking you can cancel the 2's in 2+3/2+5. You can't! Math professors secretly giggle every time a student makes this mistake and then has to sheepishly erase their work. The projection formula may look tempting, but those u's are staying right where they are!

The mathematical pun here is absolutely brilliant! The meme shows a Gram matrix (that blue rectangular monstrosity with all those vector dot products) arranged to look like the Swedish flag. The joke hinges on the fact that Jesus died on a cross (×), but in this alternate universe, he died on a dot product (·) instead. For the uninitiated math warriors, a dot product is an operation between vectors that gives you a scalar (single number), while a cross product gives you another vector. The Gram matrix shown here is entirely made of dot products between vectors v₁, v₂, etc. - making it the perfect mathematical crucifixion alternative! This is the kind of joke that would make a linear algebra professor snort coffee through their nose during office hours. Pure mathematical blasphemy!