Maths

Question 1

When is Arc Length used?

What is the formula?

Answer 1

To find the length of a side of a part of the circumference of a circle

To calculate it we use the formula
AL= angle/360 x PIE D

Question 2

When is Sector Area used?

What is the formula?

Answer 2

Sector Area is used to calculate the area (not length- that would be arc length) of a major or minor section of a circle

The formula is
SA= angle/ 360 x PIE R squared

Question 3

When Pythagoras used ?

What is the formula?

Answer 3

Pythagorus is used to calculate the length of a side of a right angled triangle

c2= a2 + b2

Question 4

How do you find the angle, when given a percentage, using a pie chart and vice versa

Answer 4

To find an angle you do
percentage / 100 x 360

to find the percentage you use
# / 100 x 360

Question 5

When is standard deviation used?

What is the formula - will be given on formula sheet.

Answer 5

Standard deviation finds the average distance each data point is from mean

The formula is

SD= squareroot of E(x- mean) squared / n-1

Question 6

how do you ‘draw the line if y=2x-3 or y=3x+2 or y=-2+2’ ?

Answer 6

Set up a table of x values and use formula to find y values

plot the points on your graph

draw the lines through the points

Question 7

when is y=mx+c used?

Answer 7

When we have the gradient and y intercept

Question 8

When is m= v/h used?

what’s used otherwise?

Answer 8

If we are given a triangle but if given a coordinate we use :
m= y2-y1 / x2-x1

Question 9

When two perpendicular gradients are multiplied, what do we get?

Answer 9

-1

Question 10

If you only have one point and a gradient, how do you find the equation of a straight line?

Answer 10

y-b = m(x-a)

Question 11

What is Simple Interest?

How do we find it?

Answer 11

Simple Internet is the money paid out each year buts not added to your account.

We find it using
SI= % for one year x #of years

Question 12

What is compound interest?

How do we find it?

Answer 12

Compound interest is used when the interest that is calculated is added to your account each year.

We find it using a calculator by
CI= amount invested x % increase or decrease squared to the amount of years

Question 13

What is simultaneous equations?

How do we find it by graph?

Answer 13

Simultaneous equations are used to find the solution that fits both equations given.

By graph we find them by looking for the point of intersection

• draw both lines
• find the coordinate of the POI

Question 14

How do we find simultaneous equations algebraically?

Answer 14

Crate equal Coefficients by multiplying

Take one equation away from the other

Substitution the answer you just got into one of the equations

MAKE ANSWERS CLEAR

Question 15

a transformation of (x+b) squared moves the graph where?

Answer 15

In x direction and -b places

Question 16

How do you sketch quadratics in the form of y=(x-a) (x+b)

Answer 16

state the roots

Find the axis of symmetry (add routes and divide by 2)

Find the turning point (sub axis of symmetry into equation)

Find y intercept (sub x=0)

Draw

Question 17

If a quadratic equation can not be factorised, what do we use? Usually in the form
ax squared + bx + c= 0

Answer 17

The Quadratic Formula

Question 18

What are the 3 conditions for crossing the x axis?

How do we know which is which?

Answer 18

Two real and distinct roots
- If b squared - 4ac is more than 0

Two real and equal roots
- If b squared - 4ac is equal to 0

No real roots
- If b squares - 4ac is less than zero

Question 19

What is the discriminant?

Answer 19

The discriminant is the part of the quadratic formula in the square root. It is used to find the condition of crossing the x axis.

example - determine the nature of the roots.

Question 20

Key features of the Sine graph

Answer 20

maximum value is 1

Minimum value is -1

period is 360 degrees

in the shape of a N

Question 21

Key features of a cosine graph

Answer 21

Maximum value if 1

Minimum value of -1

Period is 360

In the shape of a V

Question 22

y= a sin/cos b x +/- c

what does a, b and c affect

Answer 22

a affects the height of the graph.

b affects how many waves are on the graph ( length of a period)

c moves the graph up or down by the number