How do you differentiate f(x)=e^sqrt(1/x^2-x)f(x)=e1x2x using the chain rule.?

2 Answers
Aug 11, 2018

dy/dx = e^(sqrt(1/x - x^2)) . (1/(2sqrt(1/x - x^2))(-1/x^2-2x))dydx=e1xx2.⎜ ⎜121xx2(1x22x)⎟ ⎟

Explanation:

Given,
f(x)=e^sqrt(1/x^2 -x)f(x)=e1x2x
Let
y=f(x)y=f(x)
Then,
y=e^sqrt(1/x^2 -x)y=e1x2x
Let,
u=sqrt(1/x - x^2)u=1xx2
Then,
y=e^uy=eu
Differentiating both sides, wrt x

dy/dx = e^u . (du)/(dx)dydx=eu.dudx

Now,
u=sqrt(1/x - x^2)u=1xx2

Let,
v=1/x - x^2v=1xx2
Then,
u=sqrtvu=v
Differentiating both sides, wrt x

(du)/(dx) = 1/(2sqrtv)(dv)/(dx)dudx=12vdvdx

Thus,

dy/dx = e^u 1/(2sqrtv)(dv)/(dx)dydx=eu12vdvdx
Again,

v =1/x - x^2 v=1xx2
Let
r = 1/xr=1x
Differentiating wrt x
(dv)/(dx)=-1/x^2dvdx=1x2
s = x^2s=x2
Differentiating wrt x
(ds)/(dx)=2xdsdx=2x
now,
v=r-sv=rs

Differentiating wrt x
(dv)/(dx)=(dr)/(dx)-(ds)/(dx)dvdx=drdxdsdx
Thus,
(dv)/(dx)=-1/x^2-2xdvdx=1x22x
Substituting for v & (dv)/(dx)v&dvdx in (du)/(dx)dudx

(du)/(dx) = 1/(2sqrtv)(dv)/(dx)dudx=12vdvdx
(du)/(dx) = 1/(2sqrt(1/x - x^2))(-1/x^2-2x)dudx=121xx2(1x22x)

Substituting for u & (du)/(dx)u&dudx in dy/dxdydx

dy/dx = e^u . (du)/(dx)dydx=eu.dudx

dy/dx = e^(sqrt(1/x - x^2)) . (1/(2sqrt(1/x - x^2))(-1/x^2-2x))dydx=e1xx2.⎜ ⎜121xx2(1x22x)⎟ ⎟

Aug 11, 2018

:.(dy)/(dx)=-1/2(2/x^3+1)e^sqrt(1/x^2-x)/sqrt(1/x^2-x)

Explanation:

Here ,

f(x)=y=e^sqrt(1/x^2-x)

Let ,

y=e^u , u=sqrtv and v=1/x^2-x=x^-2-x

(dy)/(dx)=e^u , (du)/(dv)=1/(2sqrtv) and (dv)/(dx)=-2x^-3-1=(-2)/x^3-1

Using Chain Rule:

color(blue)((dy)/(dx)=(dy)/(du)*(du)/(dv)(dv)/(dx)

(dy)/(dx)=e^u 1/(2sqrtv)(-2/x^3-1)

Subst. back u=sqrtv

(dy)/(dx)=e^sqrtv 1/(2sqrtv)(-2/x^3-1)

Now ,subst. v=1/x^2-x

:.(dy)/(dx)=e^sqrt(1/x^2-x)1/(2sqrt(1/x^2-x))(-2/x^3-1)

:.(dy)/(dx)=-1/2(2/x^3+1)e^sqrt(1/x^2-x)/sqrt(1/x^2-x)