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Mathematics
Problem
Let
x
=
t
2
x=t^{2}
x
=
t
2
and
y
=
t
3
y=t^{3}
y
=
t
3
, where
t
∈
R
t\in\mathbb R
t
∈
R
. Show that the second derivative obtained by differentiating
d
y
d
x
\dfrac{dy}{dx}
d
x
d
y
with respect to
x
x
x
satisfies
d
2
y
d
x
2
=
f
′
(
t
)
g
′
′
(
t
)
−
g
′
(
t
)
f
′
′
(
t
)
[
f
′
(
t
)
]
3
,
\frac{d^{2}y}{dx^{2}}=\frac{f'(t)\,g''(t)-g'(t)\,f''(t)}{[f'(t)]^{3}},
d
x
2
d
2
y
=
[
f
′
(
t
)
]
3
f
′
(
t
)
g
′′
(
t
)
−
g
′
(
t
)
f
′′
(
t
)
,
where
f
(
t
)
=
t
2
f(t)=t^{2}
f
(
t
)
=
t
2
and
g
(
t
)
=
t
3
g(t)=t^{3}
g
(
t
)
=
t
3
, and hence find
d
2
y
d
x
2
\dfrac{d^{2}y}{dx^{2}}
d
x
2
d
2
y
in terms of
t
t
t
.
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