On November 12, 2025, Google is highlighting one of the most famous math formulas in the world. Its doodle in India features the quadratic equation ax² + bx + c = 0. The doodle shows how this simple ...

We can calculate the gradient of a tangent to a curve by differentiating. In order to find the equation of a tangent, we: Differentiate the equation of the curve Substitute the \(x\) value into the ...