Trig Flashcards
Sin =
O/H
Cos =
A/H
Tan =
O/A
Hypotenuse can never be _____. Why?
Negative
Can’t divide by a negative
Describe the cast diagram
Describe the cast diagram
What are reductions
We can write a trig ratio of a non-acute angle in terms of a ratio of an acute angle. Reduction formulae is a method whereby we can take an angle in any quadrant and reduce it to an angle in the first quadrant, this is because all trigonometric ratios are positive in the first quadrant.
Describe the CAST diagram, including reductions and revolutions
Sin and cos are _____.
Complementary. Meaning when they add to 90 theyre =
Sin(90-θ)=?
+cos θ
Cos(90-θ)=?
+sin θ
sin(90+ θ)=?
+cos θ
Cos(90+ θ)=?
-sin θ
Sin(270-θ)=?
+Cos θ
Cos(270-θ)=?
-sin θ
Sin(270+ θ)=?
-cos θ
Cos(270+ θ)=?
+Sin θ
Remember: ____+_____=1
cos2 + sin2
Tan =
Sin/cos
Special triangles?
Period on a trig graph is?
the degrees is takes to complete one full cycle (e.g. 360 or 180)
Amplitude on a trig graph is? Where is it in the graph’s equation?
The height of a graph above the middle.
Represented by ‘a’
Horizontal shift on a trig graph is? Where is it in the graph’s equation?
Movement of the entire graph left (+) or right (-).
Represented by ‘p’
Vertical shift on a trig graph is? Where is it in the graph’s equation?
Movement of the entire graph up (+) or down (-).
Represented by ‘q’.
standard cos and sin equations?
y = asin(θ ± p) ± q
y = acos(θ ± p) ± q
sin rule?
a/sinA = b/sinB = c/sinC
Cos rule?
a2 = b2+c2 - 2bc . Cos(A)
You can only cancel something in a fraction when?
It’s one term (no pluses or minuses - if there are then FACTORISE)
