Question

how do i find the second derivative of xsinx?

Answer 1

you have to find first derivative first

Answer 2

that is a good first step, yes

Answer 3

for the first derivative i got xcosx+sinx

Answer 4

yes that is it. now you have to use the product rule again on the first part

Answer 5

ok so then i got x(-sinx)+cosx+sinx now what?

Answer 6

a mistake here

Answer 7

you got the derivative of the first part correct but you forgot to take the derivative of sin(x)

Answer 8

should get
\[-x\sin(x)+\cos(x)+\cos(x)\]

Answer 9

oh so x(-sinx)+2cosx? since sinx cosx and u add them?

Answer 10

yes you will probably see it written as
\[2\cos(x)-x\sin(x)\]

Answer 11

oh so x(-sinx)+2cosx? since sinx cosx and u add them?

Answer 12

oh got it ,does it matter the order in which u put cos and sin?

Answer 13

nope, one of those property whose name I can't recall

Answer 14

k thanks