Question

d/dx(x^3-2x-1)
want answer asap....

Answer 1

${\underline{\sf{Given}}}$

$\sf\:y=x^3-2x-1$

${\underline{\sf{To\:Find}}}$

dy/dx

${\underline{\sf{Solution}}}$

We have,$\sf\:y=x^3-2x-1$

Now Differentiate with respect to x

$\sf\dfrac{dy}{dx}=\dfrac{d(x^3-2x-1)}{dx}$

$\sf\dfrac{dy}{dx}=3x^2-2$

$\rule{200}2$

${\underline{\sf{Formula's}}}$

$1)\sf\:\frac{d(x {}^{n} )}{dx} = nx {}^{n - 1}$

$2)\sf\:\frac{d(constant)}{dx} = 0$

$3) \sf\dfrac{d( \tan \: x)}{dx} = \sec{}^{2}\: x$

$\sf4) \dfrac{d(e {}^{x}) }{dx} = {e}^{x}$

Answer 2

Answer:

Given

\sf\:y=x^3-2x-1y=x

3

−2x−1

{\underline{\sf{To\:Find}}}

ToFind

dy/dx

{\underline{\sf{Solution}}}

Solution

We have,\sf\:y=x^3-2x-1y=x

3

−2x−1

Now Differentiate with respect to x

\sf\dfrac{dy}{dx}=\dfrac{d(x^3-2x-1)}{dx}

dx

dy

=

dx

d(x

3

−2x−1)

\sf\dfrac{dy}{dx}=3x^2-2

dx

dy

=3x

2

−2

\rule{200}2

{\underline{\sf{Formula's}}}

Formula

′

s

1)\sf\:\frac{d(x {}^{n} )}{dx} = nx {}^{n - 1}1)

dx

d(x

n

)

=nx

n−1

2)\sf\:\frac{d(constant)}{dx} = 02)

dx

d(constant)

=0

3) \sf\dfrac{d( \tan \: x)}{dx} = \sec{}^{2}\: x3)

dx

d(tanx)

=sec

2

x

\sf4) \dfrac{d(e {}^{x}) }{dx} = {e}^{x}4)

dx

d(e

x

)

=e

x