Algebra

Question 1

What is the quadratic formula?

Answer 1

x = (-b ± √ b² - 4(a × c)) ÷ 2a

Question 2

What is the equation for the quadratic formula?

Answer 2

x = ax² + bx + c = 0

Question 3

What is Pythagoras’ theorm?

Answer 3

a² + b² = c²

Question 4

What is the equation for the area of a triangle?

Answer 4

1/2 base × height

Question 5

What is the cosine rule?

Answer 5

a² = b² + c² - 2bcCosA

Question 6

What is the sine rule?

Answer 6

SineA/a = SinB/b =SinC/c

Question 7

How do you use sine to work out the area of a triangle?

Answer 7

1/2 abSinC

Question 8

What is SOHCAHTOA?

Answer 8

SinX = Opposite/Hypotenuse
CosX = Adjacent /Hypotenuse
TanX = Opposite/Adjacent

Question 9

What are the 3 rules for surds?

Answer 9

1. √a × √a = a
2. √a × √b = √a × b
3. √a ÷ √b = √a ÷ b

Question 10

In the equation y = mx + c

What does the m stand for?

Answer 10

m stands for the gradient.

Question 11

In the equation y = mx + c

What does the c stand for?

Answer 11

c stands for the y intercept. (where the line crosses the y-axis)

Question 12

How do you work out the gradient of a line?

Answer 12

Rise/run

Question 13

How do you calculate volume?

Answer 13

Volume = cross sectional area × length

Question 14

In a cumulative frequency graph, The cumulative frequency is what?

Answer 14

The previous frequency + current frequency

Question 15

When plotting a cumulative frequency graph do you use the end or midpoints?

Answer 15

You use the end points.

Question 16

How do you calculate the mean from a frequency table?

Answer 16

Frequency × midpoint for all ranges + together ÷ by total frequency

Question 17

How do you calculate the upper bound

Answer 17

You either × or ÷ the upper bound by the other lower bound value.

Question 18

How do you calculate the lower bound?

Answer 18

You either × or ÷ the lower bound by the other upper bound value.

Question 19

How do you calculate the bound?

Answer 19

You calculate the middle of the upper bound either × or ÷ by the other lower bound value and the lower bound either × or ÷ by the other upper bound value

Question 20

What is the frequency in a histogram?

Answer 20

The frequency in a histogram is the area of the bars (Class width × frequency density)

Question 21

How do you calculate a mean from a histogram table?

Answer 21

((Frequency × midpoint) + together) ÷ total frequency

Question 22

What is the difference between an equation and an identity?

Answer 22

An equation has a solution for a specific value of x to make the equation true for example 5n - 7 = 8
and an identity does not need a specific value for x to be true for example 2(n + 3) = 2n + 6 which simplifies to 2n + 6 = 2n + 6

Question 23

How do you calculate frequency density?

Answer 23

Frequency × class width

Question 24

How wide are the bars on a frequency density graph?

Answer 24

The bars are as wide as the classes

Question 25

What is the equation for density?

Answer 25

Density = mass ÷ volume