Page 91 - Math SL HB Sem 1

CIRCULAII F'UNCTIONS AND TITI(;ONO]VIEI'ItY

,-l::^.".e.
ln*" other rrigc,nomelric ratios krorvn as the reciprocal trigonometric
ratros: cosecant'secant
and cotangent ratios. These are derined as

.r" B: l. sin d+o
sln 1,

sec 0 .cos 0 +0
cos g

I
cotd= .(rne*0
tan9'

ANGLE OFANY MAGNII'UDE

'fhe
first quadrant (acute angles)
On the unit circle, if I AOl, = go,
p
then the coordinates of are (cosd, sind)

f
{.r, y) = (cos 0, sio 0)

radian measure of
I the anBle 0
I
I

0 x-cosd
),-sin0

The second quadrant (obtuse angles)

We will apply the definitions lor sin d and cos d to obtuse angles
srn I 50" = sin ..... . (in radians) :

:
sin 30" sin.......

cosl50' = cos..... . (in radians):

:
cos 30o cos.......

4-7