Section 13.3a

Section 13.3a

General Angles

1.) Find The 6 trig functions for angle Ɵ

x

y

y

x

r

Ɵ

sin Ɵ =

cos Ɵ=

tan Ɵ =

csc Ɵ =

sec Ɵ =

cot Ɵ =

Def: Reference Angles: The reference angle is the acute angle formed by the terminal side of the given angle and the x-axis.

Def: Reference Triangles: Reference triangles are formed using reference angles and the perpendicular segment to the x-axis.

x

y

III

III IV

Quadrants

Function Quadrant

I II III IV

sin or csc

cos or sec

tan or cot

+

+

+

+

+

+

- -

- -

- -

x = +y = +

x = -y = +

x = -y = -

x = +y = -

sin yr

cos xr

tan yx

All Students Take Calculus

A S T C - All Students Take Calculus!

x

y

Ɵ

2.) Find The 6 trig functions for angle that passes throughThe point P(-3,4)

Sin Ɵ =

Cos Ɵ=

Tan Ɵ =

Csc Ɵ =

Sec Ɵ =

Cot Ɵ =

3.) Find The 6 trig functions for angle 300°

x

y

y

x

r

Ɵ

Sin Ɵ =

Cos Ɵ=

Tan Ɵ =

Csc Ɵ =

Sec Ɵ =

Cot Ɵ =

Def: Quadrantal Angles:Angles whose terminal side coincides with either the x-axis or the y-axis are called quadrantal angles.

0º

90º

360º

270º

4. Find the trig functions for the quadrantal angle 180º

5.) Find cos π

6.) Find tan π

7.) Find sin 90°

Homework

Page 790

Problems: 17-26, and 31