differentiate x*sin(x)
Let's perform the differentiation: ddx(x·sin(x))
For u1 = x and v2 = sin(x), use the differentiation rule: ddx(u1·v2) = ddx(u1)·v2 + u1·ddx(v2)
Let's perform the differentiation u1: ddx(x)
ⓘ The derivative of x is 1: ddx(x) = 1
1
Let's perform the differentiation v2: ddx(sin(x))
ⓘ The derivative of sin(x) is cos(x): ddx(sin(x)) = cos(x)
cos(x)
Let's evaluate the resulting derivative (u1·v2)': 1·sin(x) + x·cos(x)
sin(x) + x·cos(x)
Then you can resume the derivation:
ⅰ ddx(x·sin(x)) = sin(x) + x·cos(x)
sin(x) + x·cos(x)
▶Derivative:   x·cos(x) + sin(x)