IGCSE MATHS:VERIFIED QUESTIONS AND ANSWERS
IGCSE MATH
Finding a Regression Line
Reminder- a regression line is the line of best fit!!
1) Put the X and Y data points provided into two labelled columns on the calculator
2)Then add a page and select 'graphs' and 'scatter'
3)If you don't have a function, go to the menu, select 'graph' and 'scatter plot'
4) Where it says 'x' and 'y' Use the column names of the data points that pop up when you click
the button 'var' (Always check for zoom fit!!)
5) Go back to the page with the columns and in the third column go to menu and select 'statistics'
then 'linear regression (y=mx+b)'
6) This will give you the gradient and y-intercept for creating the equation of the regression line
Video Link:
https://www.google.com/search?q=how+to+find+regression+line+on+ti-
nspire+cx+ii&oq=how+to+find+regression+lin+tnspire&aqs=chrome.2.69i57j0i22i30j0i22i30i6
25j0i390l5.7219j0j7&sourceid=chrome&ie=UTF-
8#kpvalbx=__C_IY77NHMjjsAeQt4nACA_40
Correlation
The relationship between two variables. The three options for correlation types are: positive,
negative, and no correlation.
E.g. there is a positive correlation between ice cream sales and temperature. As the temperature
increases, more ice cream is sold.
Finding Y values when given X values and the equation of a line
Plug in the x value into the equation of a line to find the corresponding y value of any given
coordinate.
Remember, equations of lines are for this purpose! If you have an equation, you can plug in any
x value and find the corresponding y value.
For example, if I know the relationship between temperature and ice cream sales as a line
equation, I can plug in any temperature (x) and estimate the number of ice cream sales (y) that
will occur.
Magnitude of a Vector
, the length or size of a vector; magnitude is a scalar quantity
A magnitude is found by using pythagorean theorem. Merely replace the 'a' and 'b' with the two
numbers in your column vector and solve.
Transformations
The four types of transformations are:
1) translation
2) rotation
3) reflection
4) enlargement
You will definitely be asked to 'describe' a transformation on the exam for 2-3 points, this
requires saying:
(1) the type of transformation
(2) Either:
- the scale factor
- rotation degree and direction (e.g. clockwise 90 degrees) -translation amount (how far it moved
on the x any y axis)
-line of symmetry (the line over which the shape is reflected)
(3) the center (ONLY FOR ROTATION AND ENLARGEMENT)
-of rotation (use tracing paper to see which center would work)
-of enlargement (draw lines between corresponding vertices and their intersection is the center)
Base Graphs: y=x and y=-x
y = x comes from y=mx+c therefore the gradient is 1 and the y-intercept is 0. It is also a line
where every x coordinate is the same as the y coordinate. These are sample coordinates on the
line y=x: (2,2) (3,3) (4,4) (5,5)
Algebraic Fractions and Cross Multiplication
When you have two fractions or algebraic fractions set equal to each other, cross multiply to
create a linear equation and then solve normally
Examples of when to use:
-algebraic fractions
-sine rule
Proving vectors are parallel or points are collinear with vector expressions
If one vector is a multiple of another then they are parallel
IGCSE MATH
Finding a Regression Line
Reminder- a regression line is the line of best fit!!
1) Put the X and Y data points provided into two labelled columns on the calculator
2)Then add a page and select 'graphs' and 'scatter'
3)If you don't have a function, go to the menu, select 'graph' and 'scatter plot'
4) Where it says 'x' and 'y' Use the column names of the data points that pop up when you click
the button 'var' (Always check for zoom fit!!)
5) Go back to the page with the columns and in the third column go to menu and select 'statistics'
then 'linear regression (y=mx+b)'
6) This will give you the gradient and y-intercept for creating the equation of the regression line
Video Link:
https://www.google.com/search?q=how+to+find+regression+line+on+ti-
nspire+cx+ii&oq=how+to+find+regression+lin+tnspire&aqs=chrome.2.69i57j0i22i30j0i22i30i6
25j0i390l5.7219j0j7&sourceid=chrome&ie=UTF-
8#kpvalbx=__C_IY77NHMjjsAeQt4nACA_40
Correlation
The relationship between two variables. The three options for correlation types are: positive,
negative, and no correlation.
E.g. there is a positive correlation between ice cream sales and temperature. As the temperature
increases, more ice cream is sold.
Finding Y values when given X values and the equation of a line
Plug in the x value into the equation of a line to find the corresponding y value of any given
coordinate.
Remember, equations of lines are for this purpose! If you have an equation, you can plug in any
x value and find the corresponding y value.
For example, if I know the relationship between temperature and ice cream sales as a line
equation, I can plug in any temperature (x) and estimate the number of ice cream sales (y) that
will occur.
Magnitude of a Vector
, the length or size of a vector; magnitude is a scalar quantity
A magnitude is found by using pythagorean theorem. Merely replace the 'a' and 'b' with the two
numbers in your column vector and solve.
Transformations
The four types of transformations are:
1) translation
2) rotation
3) reflection
4) enlargement
You will definitely be asked to 'describe' a transformation on the exam for 2-3 points, this
requires saying:
(1) the type of transformation
(2) Either:
- the scale factor
- rotation degree and direction (e.g. clockwise 90 degrees) -translation amount (how far it moved
on the x any y axis)
-line of symmetry (the line over which the shape is reflected)
(3) the center (ONLY FOR ROTATION AND ENLARGEMENT)
-of rotation (use tracing paper to see which center would work)
-of enlargement (draw lines between corresponding vertices and their intersection is the center)
Base Graphs: y=x and y=-x
y = x comes from y=mx+c therefore the gradient is 1 and the y-intercept is 0. It is also a line
where every x coordinate is the same as the y coordinate. These are sample coordinates on the
line y=x: (2,2) (3,3) (4,4) (5,5)
Algebraic Fractions and Cross Multiplication
When you have two fractions or algebraic fractions set equal to each other, cross multiply to
create a linear equation and then solve normally
Examples of when to use:
-algebraic fractions
-sine rule
Proving vectors are parallel or points are collinear with vector expressions
If one vector is a multiple of another then they are parallel
