EDEXCEL A-LEVEL PURE MATHS (9): TRIGONOMETRIC RATIOS

What is the cosine rule?

- The cosine rule can be used to work out missing sides or angles in triangles.

- There are two variations of the cosine rule:

1) a² = b² + c² - 2bc cos A (used to find a missing side if you know the angle between them).

2) cos A = (b² + c² - a²) ÷ 2bc (used to find an angle if you know all three sides).

How can you prove the cosine rule?

What is an example of using the cosine rule to calculate the length of a side?

What is an example of using the cosine rule to calculate the length of a side in a question involving bearings?

What is an example of using the cosine rule to calculate the size of an angle?

What is an example of using the cosine rule to calculate the length of a side in a question involving sketches with descriptions?

What is the Sine rule?

- You can use the sine rule to work out missing sides or angles in triangles.

- There are two variations of the sine rule:

1) (a ÷ sin A) = (b ÷ sin B) = (c ÷ sin C) (can be used to find the length of a missing side).

2) (sin A ÷ a) = (sin B÷ b) = (sin C÷ c) (can be used to find a missing angle).

How can you prove the Sine rule?

What is an example of finding missing lengths using the Sine rule?

What is an example of finding missing angles using the Sine rule?

Why does the Sine rule sometimes produce two possible triangles with a missing angle?

What is the formula for the area of any triangle?

Area = ½ab x sin C

What is the proof of ½ab x sin C?

What is an example of using ½ab x sin C to calculate the area of a triangle?

What is an example of using ½ab x sin C to find a length?

What is graph of y = sin Θ?

What is graph of y = cos Θ?

What is graph of y = tan Θ?

What are examples of questions involving the sketching of trigonometric graphs?

What are examples of transforming trigonometric graphs?

What are more xamples of transforming trigonometric graphs?

EDEXCEL A-LEVEL PURE MATHS CHAPTER NINE: TRIGONOMETRIC RATIOS

(MAKE SURE YOU KNOW THE FOLLOWING)