The eternal battle between mathematical purity and engineering practicality in one glorious meme! The mathematician is having an existential crisis over integrating sin(dx) because technically it's a meaningless expression—you can't integrate with respect to dx when dx is inside the function.
Meanwhile, the engineer swoops in with the small-angle approximation (sin(θ) ≈ θ for small angles) and just... solves it. No tears, no crisis, just results. Sure, it's mathematically blasphemous, but does the bridge fall down? No? Then it's correct enough!
This is why engineers get invited to parties and mathematicians stay home proving why the party can't theoretically exist.