Download Name: Casey Stephens Date: 7/24/2013 School: DHS Facilitator

Name: Casey Stephens
Date: 7/24/2013
School: DHS
Facilitator: Jessica Hyatt
10.01 Trigonometric Ratios
1. Find the values of the following in simplest fraction form then divide to represent in decimal form.
AB = 13, AC = 12, BC = 5
Fraction form
opp
Sin A =
hypotenuse
Cos A =
Tan A =
Decimal form
Sin A =
adj
hypot
Cos A =
opp
adj
Tan A =
2. Use the Online Trigonometric Table of Values to find the following:
Sin 10o = 0.17
Tan 45o = 1
Cos 80 o = 0.17
3. Use a scientific calculator to find the following values. (Web 2.0 Calc)
Sin 80 o = 0.9
Cos 45o = 0.7
Tan 77o = 4.3
4. Open the Trig Functions activity. Use the interactive to answer the following questions.
 How does the value of sinA change as
increases and decreases? sinA increases while angle a
decreases

How does the value of cosA change as
increases and decreases? CosA decreases as angle a
increases

What happens to the value of tanA as you increase

How do the reciprocal values change compared to the other functions? as they're the reciprocals
of the other ratios, they just work the opposite way
? They both rise

Which values are always less than 1? Negative values

When are sine and cosine equal? for any given value of a sine function; you can find an equal
value of a cosine function
5. Identify the relationship between the sine and cosine of complementary angles.
Using the Online Trigonometric Table of Values or the Trig Functions activity, you can start by stating
the sine and cosine for the complementary angles 40° and 50°
 sin 40° = 0.64 cos 40° = 0.76
sin 50° = 0.7 cos 50° = 0.64
Think of two complementary angles and list the sine and cosine for each.
Complementary angles
° and
°
 sin
°=
cos
°=
sin
°=
cos
°=

How does the value of sine and cosine of complementary angles relate? the sine of one equals
the cosine of the other

Explain in your words why this relationship of sine and cosine holds for complementary angles.