Intro to the unit circle

sin B = Cos C

cos A = Sin C

Sin A = Cos B

tan A = Cot B

cos(37) = 14/x

cos(37) = x/14

tan(37)=x/14

sin(37)=14/x

7 / 24

24 / 25

7 / 25

24 / 7

$$6^{\circ}$$

$$20^{\circ}$$

$$43^{\circ}$$

$$47^{\circ}$$

$$a=0.9397,\ b=0.3420$$

$$a=0.9397,\ b=-0.3420$$

$$a=-0.9397,\ b=0.3420$$

$$\alpha=-0.9397,\ b=-0.3420$$

(1 / 2 , 1 / 2)

(-√3 / 2 , 1/2)

(1 / 2 , -√3 / 2)

(-√3 / 2 , -1/2)

A point (x, y) on the circle

The circumference of the circle

The angle θ

The radius of the circle

(1 / 2 , 1 / 2)

(-√3 / 2 , 1/2)

(1 / 2 , -√3 / 2)

(-√3 / 2 , -1/2)

t = π/6

t = 5π/4

t = π

t = -π/3

-1 to 1

0 to 1

-2 to 2

-1 to 0

-1 to 1

0 to 1

-1 to 0

-2 to 2

A function that is constant

A function that repeats its values at regular intervals

A function that is always increasing

A function that has no maximum or minimum

Cosine and secant are odd

Sine and cosecant are even

Cosine and secant are even

Sine and tangent are odd

0

1/2

√3/2

-1/2

cos(−7π/2) = 0, sin(−t) = −4/5

cos(−7π/2) = 1, sin(−t) = 4/5

cos(−7π/2) = −1, sin(−t) = 4/5

cos(−7π/2) = 0, sin(−t) = 4/5