Key(^) points
P1^
7
KEy POINTS
1 The point (x, y) at angle θ on the unit circle centre (0, 0) has co-ordinates
(cos θ, sin θ) for all θ.
2 The graphs of sin θ, cos θ and tan θ are as shown below.
3 tanθ≡cosinsθθ
4 sin^2 θ + cos^2 θ ≡ 1.
5 Angles can be measured in radians. π radians = 180°.
6 For a circle of radius r, arc length = rθ
area of sector = 21 r^2 θ} (θ in radians).
7 The graph of y = f(x) + s is a translation of the graph of y = f(x) by
0
s
.
8 The graph of y = f(x – t) is a translation of the graph of y = f(x) by t
0
.
9 The graph of y = –f(x) is a reflection of the graph of y = f(x) in the x axis.
10 The graph of y = af(x) is a one-way stretch of the graph of y = f(x) with scale
factor a
parallel to the y axis.
11 The graph of y = f(ax) is a one-way stretch of the graph of y = f(x) with scale
factor^1 a
parallel to the x axis.θsin θ–360° –180° 0° 180° 360° θcos θθtan θ–360° –180° 0° 180° 360°–360° –180° 0° 180° 360°1–11–1