Algebra 2 chapter 13 final

30-60-90 triangle

- Across from 30 = 1 - Across from 60 = √3 - Across from 90 = 2

45- 45- 90 triangle

- Across from 45 = 1 - Across from 90 = √2

Law of Cosines

- a^2 = b^2 + c^2 -2ab cos A

cotangent

- cot - 1 / tan - adjacent / opposite

Cosecant

- csc - 1 / sin - hypotenuse / opposite

Secant

- sec - 1 / cos - hypotenuse / adjacent

Finding the exact of each trig function

1. Draw angle 2. Form a triangle by drawing a line to the x-axis 3. Find the reference angle and label the sides of your triangle 4. Find the value of the trig function 5. Determine the sign

Finding the terminal side of Ø

1. Plot the ordered pair 2. Draw a right triangle to the origin and the x-axis 3. Ø is always at the origin 4. Use a^2 + b^2 = c^2 to find the hypotenuse 5. Now finally find all the trig functions

SSS

1. Use the law of cosines to find the largest angle 2. Use the law of sines to find the 2nd angle 3. Use the triangle angle sum theorem to find the 3rd angle

SAS

1. Use the law of cosines to find the missing 3rd side 2. Use the law of sines to find the smallest angle 3. Use the triangle angle sum theorem to find the 3rd angle

Law of sines

Sin A / a = Sin B / b = Sin C / c

To convert to degrees

multiple 180 / π

To convert to radians

multiply π / 180

Tangent

opposite / adjacent

Sin

opposite / hypotenuse

Cosine

adjacent / hypotenuse