Math Unit 5 Test Flashcards
Hypotenuse:
The longest side, always across from the Right Angle
Opposite:
Across from the INDICATED/GIVEN angle
Adjacent:
Helps form the INDICATED/GIVEN angle
SOH CAH TOH
Sin 0 = Opp/Hyp
Cos 0 = Adj/Hyp
Tan 0 = Opp/adj
There are 3 “Secondary Trig Ratios” They are…
the Reciprocals of the “Primary Trig Ratios”
Cosecant
Csc 0 = Hyp/Opp
Secant
Sec 0 = Hyp/Adj
Cotangent
Cot 0 = Adj/Opp
Angles 30°, 45° and 60° often occur in trigonometry
they are called SPECIAL angles
the triangles in which they are found are called SPECIAL TRIANGLES
What does ET look like?
Equilateral triangle split in half
Degrees - 90 and 60 at the bottom together, and 30 at the top
Sides - √3 (adj or opp), 2 (hyp), 1 (adj or opp)
What does IRT look like?
Triangle split in half
Degrees - 45, 45, 90
Sides - 1 (adj or opp), 1 (adj or opp), √2
When the angle is 30 what is cos?
√3/2
When the angle is 30 what is sin?
½
When the angle is 30 what is tan?
1/√3
When the angle is 45 what is cos?
1/√2
When the angle is 45 what is sin?
1/√2
When the angle is 45 what is tan?
1
When the angle is 60 what is cos?
½
When the angle is 60 what is sin?
√3/2
When the angle is 60 what is tan?
√3/1
From the UNIT CIRCLE diagram, we can see a rule in when RATIOS ARE POSITIVE in each of the 4 quadrants
This is often called the CAST RULE
C in
bottom right
A in
top right
S in
top left
T in
bottom left
A is
I
S is
II
T is
III
C is
IV
A range
0 - 90
S range
90 - 180
T range
180 - 270
C range
270 - 360
Cosine is positive in
C
All ratios are positive in
A
Sine is positive in
S
Tangent is positive in
T
To Find the exact value of the following (use a well-labelled diagram)
Drop the perpendicular to the x-axis after drawing the angle
Subtract the max angle from each quadrant to find the value