I need help to find derivative of: ddx(x+1)sinx
i tried to do something like this..
(x+1)sinx⋅ln(x+1)=sinx(x+1)sin(x)−1⋅ln(x+1)−(x+1)sin(x)⋅1x+1=sinx(x+1)sin(x)−1ln(x+1)−(x+1)sinxx+1
I tried another way:
(x+1)sinx=ln(x+1)sinx=sin(x)ln(x+1)=cos⋅ln(x+1)+sin(x)⋅1x+1=cos(x)ln(x+1)+sin(x)x+1
ok i got the solution! I put it there, maybe this will help someone!
i used this rule : ea=ea⋅ln⋅e
(x+1)sinx=esinx⋅ln(x+1)=esinx⋅ln(x+1)⋅cosx⋅ln(x+1)+sinx⋅1x+1=(x+1)(cosxln(x+1)+sinxx+1)
Answer
You have:
f(x)=(x+1)sinx, so lnf=sinxln(x+1). Now we have:
ddxlnf=1fdfdx=ddx[sinxln(x+1)].
You can now solve for f′ once you expand the LHS of the equation.
Cheers!
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