Trig Methods Flashcards
Sine Rules, Cosine etc
What is Pythagoras theorem?
a^2 = b^2+c^2
When to use Pythagoras theorem?
Know all 3 sides
Right angle triangle
When to use SCT?
know 2 sides and an angle
Right Angle
What are SCT rules?
Sin = O/H
Cos = A/H
Tan = O/A
When to use Sine rule?
No right angle
2 sides and 2 angles
What is the Sine rule?
a/Sin A = b/Sin B = c/Sin C
Sin A/a = Sin B/b = Sin C/c
When to use a/Sin A = b/Sin B?
When finding a Length
What does a and Sin A represent?
a = length
A = angle
When to use Sin A/a = Sin B/b?
When finding a Angle
What to do when finding a angle?
Remember to use inverse function and make sure the angles are in the range
When to use cosine rule?
No right angle
Involves 3 sides and 1 angle
What is the cosine rule for a line?
a^2 = b^2+c^2- 2bcCosA
How to use cosine rule?
Replace the a^2 = with x^2 =
What is the cosine rule for a angle?
Cos (A) = b^2+c^2-a^2/2bc
