1.9 Trigonometric ratios Flashcards
What is the cosine rule?
a^2 = b^2 + c^2 - 2bc cos(A)
Rearrange the cosine rule to find cos(A)
b^2 + c^2 - a^2
cos(A) = ————–‐——-
2bc
What is the sine rule
a/sin(A) = b/sin(B) = c/sin(C)
sin(A)/a = sin(B)/b = sin(C)/c
Using the sine rule, what are the two possible solutions for a missing angle?
sin(O) = sin(180-O)
acute and obtuse
What is the interval of sin(O)
repeats every 360
What is the interval of cos(O)
repeats every 360
What is the interval of tan(O)
repeats every 180
What are the minimum and maximum values of sin(O)
-1 and 1
What are the minimum and maximum values of cos(O)
-1 and 1
What are the minimum and maximum values of tan(O)
No minimum and maximum values
Where does sin(O) cross the x-axis
-180, 0, 180, 360
Where does cos(O) cross the x-axis
-90, 90, 270, 450
Where does tan(O) cross the x-axis
-180, 0, 180, 360
Where are the asymptotes of tan(O)
vertical at x =
