Math Pro
about
qns
questions
progress
Question 0521
Sigma Notation
2021 Paper 1 Question 5 Variant
Question
Generate new
(a)
Express
x
(
x
+
2
)
(
x
+
3
)
(
x
+
4
)
\frac{x}{(x + 2)(x + 3)(x + 4)}
(
x
+
2
)
(
x
+
3
)
(
x
+
4
)
x
in partial fractions.
[3]
(b)
Hence find, in terms of
n
,
{n,}
n
,
∑
r
=
1
n
r
(
r
+
2
)
(
r
+
3
)
(
r
+
4
)
.
\sum_{r=1}^n \frac{r}{(r + 2)(r + 3)(r + 4)}.
r
=
1
∑
n
(
r
+
2
)
(
r
+
3
)
(
r
+
4
)
r
.
[3]
(c)
State the value of
∑
r
=
1
∞
r
(
r
+
2
)
(
r
+
3
)
(
r
+
4
)
.
\sum_{r=1}^\infty \frac{r}{(r + 2)(r + 3)(r + 4)}.
r
=
1
∑
∞
(
r
+
2
)
(
r
+
3
)
(
r
+
4
)
r
.
[1]
Answer
Back to top ▲
about
questions
progress