Question

re edit question no.2

Answer 1

find the derivative of y = x^2 cos x- 2xsinx - 2cos x with respect to x.
a. x^2 sinx
b.-x^2 cosx
c.x^2 cosx
d.-x^2 sinx

Answer 2

i got the answer here letter D

Answer 3

=2xcosx-x^2sinx-(2sinx+2xcosx)+2sinx=2xcosx-x^2sinx-2sinx-2xcosx+2sinx=-x^2sinx so D

Answer 4

let's define
y / x = alpha

then sin (alpha) = 1/alpha

this equation determines alpha as a constant, therefore the relationship between y and x is linear and we have

y = alpha x

and subsequently

y' = alpha

however we defined alpha to be y/x

therefore

y' = y/x <<<answer from re edit question 1