Skip to content

Course home

1.8 Integration

1.8 Integration

EasyMediumHard
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119
Question 62

The cross-section of a industrial drainage channel is modeled by a curve C C\,C with equation

y=(x−k)2x,x>0 y = \frac{(x - k)^2}{\sqrt{x}}, \quad x > 0 y=x​(x−k)2​,x>0

where k k\,k is a positive constant.

a.

Show that

∫116(x−k)2x dx=ak2+bk+20465 \int_{1}^{16} \frac{(x - k)^2}{\sqrt{x}} \, dx = ak^2 + bk + \frac{2046}{5} ∫116​x​(x−k)2​dx=ak2+bk+52046​

where a a\,a and b b\,b are integers to be found.

[4]
b.

A sketch of the curve C C\,C and a straight line l l\,l are shown. The line l l\,l represents the water level during a flood, intersecting the curve C C\,C at point A(1,9)A(1, 9)A(1,9) and at point B(16,q)B(16, q)B(16,q), where q q\,q is a constant.

Show that k=4k = 4k=4.

Sketch of curve C and straight line l intersecting at A(1, 9) and B(16, q), with region R between them.

[2]
c.

The region R R\,R is the cross-sectional area of the water, bounded by the curve C C\,C and the line l l\,l between points A A\,A and BBB. Using the results from parts (a) and (b),

find the area of region RRR.

[4]
Markscheme

1.8 Integration Questions

  1. A Level
  2. /Maths
  3. /1.8 Integration

160 exam-style questions on WJEC A Level Maths 1.8 Integration, covering 1.8.1 Integration, 1.8.2 Integration, and 1.8.3 Integration. Each one has a worked solution and a mark scheme showing where the marks go.

Question bank