Y11 EV
1.
Integration Problems
Let f ′ (x) = 12x2 − 2.
Given that f (−1) =1, find f (x).
2.
The velocity v m s–1 of a moving body at time t seconds is given by v = 50 – 10t.
Find its acceleration in m s–2.
(a)
(b) The initial displacement s is 40 metres. Find an expression for s in terms of t.
3.
Let
(a)

5
1
3 f ( x) dx  12.
Show that

1
5
f ( x) dx   4.
(b) Find the value of
4.
2
5
1
2
The shaded region in the diagram below is bounded by f (x) =
has an area of
5.
 x  f ( x)  dx   x  f ( x)  dx.
x , x = a, and the x-axis. The shaded region
54
. Find the value of a.
3
In this question s represents displacement in metres and t represents time in seconds.
The velocity v m s–1 of a moving body is given by v = 40 – at where a is a non-zero constant.
(a)
(i)
If s = 100 when t = 0, find an expression for s in terms of a and t.
(ii)
If s = 0 when t = 0, write down an expression for s in terms of a and t.
Trains approaching a station start to slow down when they pass a point P. As a train slows down, its
velocity is given by v = 40 – at, where t = 0 at P. The station is 500 m from P.
(b)
(c)
A train M slows down so that it comes to a stop at the station.
(i)
Find the time it takes train M to come to a stop, giving your answer in terms of a.
(ii)
Hence show that a =
8
.
5
For a different train N, the value of a is 4.
Show that this train will stop before it reaches the station.
Y11 EV
6.
Integration Problems
Let f(x) = x(x – 5)2, for 0 ≤ x ≤ 6. The following diagram shows the graph of f.
Let R be the region enclosed by the x-axis and the curve of f.
(a)
Find the area of R.
(b) The diagram below shows a part of the graph of a quadratic function g(x) = x(a – x). The graph of g
crosses the x-axis when x = a.
The area of the shaded region is equal to the area of R. Find the value of a.
7.
The velocity v m s–1 of an object after t seconds is given by v(t) = 15 t  3t , for 0 ≤ t ≤ 25.
(a)
On the grid below, sketch the graph of v, clearly indicating the maximum point.
Let d be the distance travelled in the first nine seconds.
(b)
(i)
Write down an expression for d.
(ii)
Hence, write down the value of d.
Y11 EV
Integration Problems
Answers:
3
f (x) = 4x  2x + 3
1.
2.
3.
a=
(b)
2
s = ∫v d = 50t – 5t + 40

(a)
5
1
7. (a)
dv
-2
= –10 (m s )
dt
(a)
3 f x dx  3
12
 f xdx , 3 , 
5
1
53f
1
xdx
3
 f x dx    f x dx
1
5
5
1
 f  x  dx   4
1
5
(b)
4.
5.
I = 16
a=9
1 2
at  100
2
1 2
s = 40t  at
2
(a) s = 40t 
(ii)
(b)
(i)
stops at station, so v = 0
(b)
40
t=
(seconds)
a
(ii)
(c)
a=
8
5
t = 10
s = 200
since 200 < 500 train stops before the
station
6.
(a)
(b)
area = 52.1
a = 6.79
(i) d =
(ii)

9
0

9
(15 t  3t )dt , d  vdt
d = 148.5 (m)
0