HSC Exam Questions (Trigonometric Ratios) Note to students: For those who have yet to study radians, 2π = 360Β°. 1995 HSC Q3(b)
A horizontal bridge is built between points π΄ and π΅. The bridge is supported by cables
ππ and ππ , which are attached to the top of a vertical pylon ππ. 4
The section of the pylon, ππ, above the bridge is 8 metres long and β ππ π = 52Β°.
(i) Find the length of the cable ππ .
(ii) Find the size of β πππ to the nearest degree.
1997 HSC Q7(a)
By expressing secπ and tanπ in terms of sinπ and cosπ, show that 2
sec! π β tan! π = 1
1998 HSC Q1(e)
Find the exact value of sin !!+ sin !!
!. 2
1999 HSC Q3(c)
In the diagram, π΄πΆ is parallel to π·π΅, π΄π΅ is 6 cm, π΅πΆ is 3 cm and π΄πΆ is 7 cm. 4
(i) Use the cosine rule to find the size of β π΄πΆπ΅, to the nearest degree.
(ii) Hence find the size of β π·π΅πΆ, giving reasons for your answer.
2000 HSC Q1(c)
What is the exact value of cos !!? 1
2000 HSC Q5(a)
Solve tan π₯ = 2 for 0 < π₯ < 2π. 2
Express your answer in radian measure correct to two decimal places.
2000 HSC Q9(c)
The diagram shows a square π΄π΅πΆπ· of side π₯ cm, with a point π within the square, such
that ππΆ = 6 cm, ππ΅ = 2 cm and π΄π = 2 5 cm. 7
Let β ππ΅πΆ = πΌ.
(i) Using the cosine rule in triangle ππ΅πΆ, show that cosπΌ = !!!!"!!
.
(ii) By considering triangle ππ΅π΄, show that sinπΌ = !!!!"!!
.
(iii) Hence, or otherwise, show that the value of π₯ is a solution of
π₯! β 56π₯! + 640 = 0
(iv) Find π₯. Give reasons for your answer.
2001 HSC Q3(d)
The diagram shows a triangle with sides 7 cm, 13 cm and π₯ cm, and an angle of 60Β° as
marked.
Use the cosine rule to show that π₯! β 7π₯ = 120, and hence state the exact value of π₯. 4
2002 HSC Q2(c)
In the diagram, πππ is a triangle where β πππ = 45Β° and β πππ = 60Β°.
Find the exact value of the ratio !!. 3
2002 HSC Q4(b)
Find all values of π, where 0Β° β€ π β€ 360Β°, that satisfy the equation: 2
cosπ β25 = 0
Give your answer(s) to the nearest degree.
2002 HSC Q4(c)
In the diagram, πΏππ is a triangle where πΏπ = 5.2 metres, πΏπ = 8.9 metres and angle
ππΏπ = 110Β°.
(i) Find the length of ππ. 2
(ii) Calculate the area of triangle πΏππ. 2
2003 HSC Q4(a)
In the diagram, the point π is due east of π. The point π is 38 km from π and 20 km from
π. The bearing of π from π is 325Β°.
(i) What is the size of β πππ ? 1
(ii) What is the bearing of π from π? 3
2004 HSC Q9(a)
Solve 2 sin! π₯ β 3 sin π₯ β 2 = 0 for 0 β€ π₯ β€ 2π. 2
2004 HSC Q3(c)
The diagram shows a point π which is 30 km due west of the point π.
The point π is 12 km from π and has a bearing from π of 070Β°.
(i) Find the distance of π from π. 2
(ii) Find the bearing of π from π. 2
2004 HSC Q8(a)
(i) Show that cosπ tanπ = sinπ. 1
(ii) Hence solve 8 sinπ cosπ tanπ = cosecπ for 0 β€ π β€ 2π. 2
2005 HSC Q2(a)
Solve cosπ = !! for 0 β€ π β€ 2π. 2
2005 HSC Q3(b)
The lengths of the sides of a triangle are 7 cm, 8 cm and 13 cm.
(iii) Find the size of the angle opposite the longest side. 2
(iv) Find the area of the triangle. 1
2006 HSC Q1(d)
Find the value of π in the diagram. Give your answer to the nearest degree. 2
2007 HSC Q4(a)
Solve 2 sin π₯ = 1 for 0 β€ π₯ β€ 2π. 2
2008 HSC Q6(a)
Solve 2 sin! !!= 1 for βπ β€ π₯ β€ π. 3
2009 HSC Q1(d)
Find the exact value of π such that 2 cosπ = 1, where 0 β€ π β€ !!. 2
2010 HSC Q5(b)
(i) Prove that sec! π₯ + sec π₯ tan π₯ = !!!"#!!"#! !
. 1
(ii) Hence prove that 1
sec! π₯ + sec π₯ tan π₯ =1
1β sin π₯
(iii) Hence use the table of standard integrals to find the exact value of 2
11β sin π₯
!!
!ππ₯
2011 HSC Q2(b)
Find the exact values of π₯ such that 2 sin π₯ = β 3, where 0 β€ π₯ β€ 2π. 2
2011 HSC Q8(a)
In the diagram, the shop at π is 20 kilometres across the bay from the post office at π.
The distance from the shop to the lighthouse at πΏ is 22 kilometres and β πππΏ is 60Β°.
Let the distance ππΏ be π₯ kilometres.
(i) Use the cosine rule to show that π₯! β 20π₯ β 84 = 0. 1
(ii) Hence, find the distance from the post office to the lighthouse. Give your answer
to the nearest kilometre. 2
2012 HSC Q6
What are the solutions of 3 tan π₯ = β1 for 0 β€ π₯ β€ 2π?
(A) !!! and !!
!
(B) !!! and !!
!
(C) !!! and !!
!
(D) !!! and !!!
!
2013 HSC Q14(c)
The right-Ββangled triangle π΄π΅πΆ has hypotenuse π΄π΅ = 13. The point π· is on π΄πΆ such that
π·πΆ = 4, β π·π΅πΆ = !! and β π΄π΅π· = π₯.
Use the sine rule, or otherwise, find the exact value of sin π₯. 3
2014 HSC Q7
How many solutions of the equation sin π₯ β 1 tan π₯ + 2 = 0 lie between 0 and 2π?
(A) 1
(B) 2
(C) 3
(D) 4
2014 HSC Q13(d)
Chris leaves island π΄ in a boat and sails 142 km on a bearing of 078Β° to island π΅. Chris
then sails on a bearing of 191Β° for 220 km to island πΆ, as shown in the diagram.
(i) Show that the distance from island πΆ to island π΄ is approximately 210 km. 2
(ii) Chris wants to sail from island πΆ directly to island π΄. On what bearing should
Chris sail? Give your answer correct to the nearest degree. 3
2014 HSC Q15(a)
Find all solutions of 2 sin! π₯ + cos π₯ β 2 = 0, where 0 β€ π₯ β€ 2π. 3