2.Ifsin=0,4 andis an obtuse angle, determine:
a) cos b)
p
21 tan
3.Giventan=
t
2
, where 0 ° 90 °. Determine the following in terms oft:
a) sec b) cot c) cos^2 d)tan^2 sec^2
4.Given: 10 cos + 8 = 0and 180 ◦< < 360 ◦. Determine the value of:
a)cos
b)
3
tan
+ 2sin^2
5.Ifsin=
15
17
andcos < 0 find the following, without the use of a calculator:
a)cos
b)tan
c)cos^2 +sin^2
6.Find the value ofsinA+cosAwithout using a calculator, given that 13 sinA 12 = 0, wherecosA < 0.
7.If 17 cos= 8 andtan > 0 determine the following with the aid of a diagram (not a calculator):
a)
cos
sin
b) 17 sin 16 tan
8.Lis a point with co-ordinates(5; 8)on a Cartesian plane.LKforms an angle,, with the positivex-axis.
Set up a diagram and use it to answer the following questions.
a) Find the distanceLK. b)Determinesin.
c) Determinecos. d)Determinetan.
e) Determine cosec. f)Determinesec.
g) Determinecot. h) Determinesin^2 +cos^2 .
9.Given the following diagram and thatcos= ^2425.
0
y
x
A(a;b)
a)State two sets of possible values ofaandb.
b)IfOA= 100, state the values ofaandb.
c)Hence determine without the use of a calculator the value ofsin.
Chapter 5. Trigonometry 137