1. A swimmer sees the top of a lighthouse on the
edge of shore at an 18º angle. The lighthouse is
150 feet high. What is the number of feet from the
swimmer to the shore?
0.3249x = 150
Tan 18 =
0.3249
0.3249 = 1
X = ft
150
18º x

2. Other ways to remember SOH CAH TOA
Some Of Her Children Are Having Trouble Over Algebra.
Some Out-Houses Can Actually Have Totally Odorless Aromas.
She Offered Her Cat A Heaping Teaspoon Of Acid.
Soaring Over Haiti, Courageous Amelia Hit The Ocean And ...
Tom's Old Aunt Sat On Her Chair And Hollered. -- (from Ann Azevedo)

3. Other ways to remember SOH CAH TOA
Stamp Out Homework Carefully, As Having Teachers Omit Assignments.
Some Old Horse Caught Another Horse Taking Oats Away.
Some Old Hippie Caught Another Hippie Tripping On Apples.
School! Oh How Can Anyone Have Trouble Over Academics.

4. Inverse Trigonometric Ratios
Remember: Functions that are inverses of each other “undo”, or cancel each other.
The inverse of add is
The inverse of times is
The inverse of square is
subtract
divide
square root

5. Inverse Trigonometric Ratios
The inverse trigonometric functions are denoted by “-1”, so:
The inverse of sinα is sin-1α
The inverse of cosα is cos-1α
The inverse of tanα is tan-1α

6. Inverse Trigonometric Ratios
Find the value of x = sin 30
When asked to solve “sin x = 0.5”, we are being asked “the sine of what angle equals 0.5”. It is easily solved by:
sin x = 0.5
Take the inverse of each side:
sin-1(sin x) = sin-1 0.5
The inverses cancel each other, so:
x = sin = 30°
x = 0.5

7. Practice In class: Page 174 – 175, # 2 3 5 6 9 25 (6)
Homework:
Page 176 – 177, # 1 – 3, – 24 by 3’s, # 26, 27 (with hint)