im just a little confused on some simple considerations of the derivative properties do we take teh constant x into consideration? And how would u do this problem?
2007-11-04 12:52:21 · 5 answers · asked by liquid_force_evolution 2 in Science & Mathematics ➔ Mathematics
dy /dx = (1)( cos x) - (sin x)(x) - cos x
dy/dx = cos x - x sin x - cos x
dy/dx = - x sin x
2007-11-04 21:55:29 · answer #1 · answered by Como 7 · 0⤊ 1⤋
Xcosx Sinx
2017-01-12 05:21:38 · answer #2 · answered by lammy 4 · 0⤊ 0⤋
to do this use the product rule. basically it says if you have to take the derivative of F(1)*F(2), you do F'(1)*F(2) + F(1)*F'(2). so the derivative of xcosx would be cosx-xsinx. the derivative of sinx is cosx, so the final eqn would be cosx-xsinx-cosx, or simply -xsinx.
also in calc, x is never a "constant", its always a variable, just for future reference
2007-11-04 12:58:59 · answer #3 · answered by kaysaw99 2 · 1⤊ 0⤋
you need the power rule if x is a variable, so it would be [(cos x)(1)-(-sinx)(x)]-cosx
if x is a constant like you say (ie an unknown number like 5 or 9 or what ever) it would be the derivitive of cosx - derivitive of sinx, or -x(sinx)-cosx.
2007-11-04 12:59:12 · answer #4 · answered by JohnValdez 3 · 1⤊ 1⤋
easy.
1. y'= -xsinx+cosx-cosx
2. y'= -xsinx
use product rule first (udv+vdu) then the cosx's cancel out.
dont forget dx of cosx is -sinx.
2007-11-04 12:56:48 · answer #5 · answered by iamamerican 3 · 1⤊ 0⤋