Quick Tips

Question 1

What does overestimates with trapezium rule mean

Answer 1

It’s a convex graph so f ‘’(x) > 0

Question 2

What to do if modulus is involved

Answer 2

|x|= x, if x>=0
|x|= -x if x<0

Question 3

The sum (sigma) of whole numbers from 1 to n can be written as

Answer 3

n(n+1) / 2

Question 4

What does underestimates mean with trapezium rule

Answer 4

It’s concave so f ‘’(x) < 0

Question 5

Triangle congruency

Answer 5

SSS (side-side-side) makes a congruent triangle (unique)
SSA does not but if A is >=90 then it does by sin rule, or if S1 is bigger than S2 (S1-S2-A)
It is NOT unique/congruent when S2sinA < S1 <S2

Question 6

What quad shapes have perpendicular diagonals

Answer 6

Kites, Rhombi, Squares and some irregular quads

Question 7

What quad shapes have bisecting diagonals

Answer 7

Parallelograms, Rhombi, Rectangles, Squares

Question 8

Which quad shapes have symmetry around diagonals

Answer 8

Squares and Rhombi has symmetry around both.
Kites have symmetry around one

Question 9

Arcs in circles

Answer 9

L=r θ
A= (r^2 θ)/ 2