Find dy/dx when y = x^2(cos(x)).

y = x2(cos(x)) therefore we will need to use the product rule, 

dy/dx = u dv/dx + v du/dx

where u = x2 and v = cos(x)

du/dx = 2x and dv/dx = - sin(x), (don't forget the negative symbol when differentiating cosine)

dy/dx = x2(- sin(x)) + cos(x)(2x)

dy/dx = 2x(cos(x)) - x2(sin(x))

JS

Related Maths A Level answers

All answers ▸

integrate from 0 to 2: 2x*sqrt(x+2) dx


integrate by parts ln(x)/x^3


How do you find (and simplify) an expression, in terms of n, for the sum of the first n terms of the series 5 + 8 + 11 + 14 + ... ?


Differentiate y=x/sin(x)