👉 In mathematics, "qrs" refers to a mathematical expression that represents an operation performed on three variables. The expression is typically used in electrical engineering and signal processing. Here's how it looks: \[ \text{qrs} = 2\sin(3x) + 4\cos(x)\] This means that the function `qr` takes three inputs `x`, `y`, and `z`, and returns the result of a mathematical operation involving sine and cosine functions. Specifically
