Vocab and formulae for Pearson Edexcel Pure year 2 textbook. A-level mathematics.
formula for arc length.
l = r x theta
where l is the length of the arc, r is the radius and theta is the angle in radians
formula for area of a sector
A = ½ r² x theta
where A is the area, r is the radius and theta is the angle in radians
formula for area of a segment
A = ½ r² (theta - sin(theta))
where A is the area of the segment, r is the radius and theta is the angle in radians.
draw a segment
drawn
draw a sector
drawn
How to solve trigonometric equations in radians?
The same way as degrees (with CAST and graphs)
what is the small angle approximation for sin(theta)
theta
what is the small angle approximation for tan(theta)
theta
what is the small angle approximation for cos(theta)
1 - ((theta)² /2)
cosine rule
c² = a² + b² -2abcos(A)
Area (sine?) rule
A = ½ bcsinA