product rule
The rule for differentiating a product of two functions — it is not just the product of the derivatives.
For f(x)=u(x)v(x), f'(x) = u'(x)v(x) + u(x)v'(x) — differentiate the first factor times the second, plus the first times the derivative of the second.
Examples
For f(x)=x^2\sin x: f''(x) = 2x\sin x + x^2\cos x.
See also
Point table
Graph settings
Calculator