Mock Flashcards
What is the equation of a line?
Y=mx+c
M= Gradient
C= Cuts the y axis
How do you get the gradient of a line?
- Draw across the line then draw up to create a triangle
- Vertical distance/ horizontal distance=gradient 2/1=2
You can leave it in fraction form (gradients can be negative)
Important: if you get a gradient of 1 or -1 write it as x and -x.
What do you do if you get an question like (line equations):
Use the graph to obtain a formula for c in terms of n?
This means it wants you find the equation of the line, y axis is c and x axis is n
Change the line equation formula
y=mx+c
To
C=mn+c (then continue as normal)
Fractions to decimals conversions?
1/2= 0.5
1/4=0.25
3/4=0.75
1/3=0.33… (recurring)
2/3= 0.66… (recurring)
1/10= 0.1
2/10= 0.2
5/10= 0.5
etc..
1/5= 0.2
2/5= 0.4
3/5= 0.6
4/5= 0.8
How to change fractions to decimals?
Numerator/ Denominator= decimal version
How to change decimals to fractions?
!Always check to simplify!
0.7= 7/10
0.24= 24/100 = 12/50= 6/25
0.125= 125/1000=25/200= 1/8
What does deposit and balance mean?
.Deposit= upfront money
.Balance= the rest of money needed
Percentage and what do you divide them buy?
1%= divide by 100
10%= divide by 10
Percentage multipliers (increase or decrease)? (Without calculator)
Percentage multipliers (increase or decrease)? (With calculator)
1 way
Percentage / 100% x value = extra value
Value- extra value= total value
2 way
100%+ other percentage = total percentage
Total percentage of value
Total percentage/100 % x value= total value
Congruent triangles?
SSS= side side side (same)
SAS= side angle side (same)
ASA= Angle side Angle (same)
RHS= Right-angle hypotenuse side (same + two right angles + longest side)
How to tell if a triangle has a hypotenuse?
The hypotenuse of a right triangle is always the side opposite the right angle.
How answer an exam question on Congruent triangles?
- Highlight and re draw the triangles mentioned in the question.
- Bulletpoint answers that’s shows they congruent give reasons
- Use information in question and in diagram
- Concluding statement
What is Standard form and how to write in standard form?
Ax10^power
A= alway a number between 1 and 10
How to write in standard form:
1. Put a decimal between the number to make below 10
2. Count from the decimal point to end= power
Standard form with decimal is already in the number?
When working with numbers with a decimal already, you count backwards to it.
Writing numbers which are already in standard form out of it you do?
- Write A out
- Then count backwards or forwards (moving decimal point) (depending if it’s negative or positive) based on the power
- Then fill in the 0s
- If it’s negative add a 0 after the new decimal point
Exam question on standard form?
- Get rid of the brackets
- All multiplication so you can change the order to make it easier
- Indices law add the indices don’t work them out
Exam question standard form?
- Get rid of brackets
- Not all multiplication so can’t do it in any order
- Turn into fraction
- Law of indices
Working with indices, what does these mean?
Evaluate
Calculate
Workout
All means = find the answer
All five index laws?
The fifth index law?
What is the power of this number: 5?
Numbers without a seen power always have the power of 1
Exam question using index rule 5?
Exam question using index notation 5?
Fractional indices using the fourth rule?
- Carry out the rule
- The root of the number is what you multiple itself root to get itself
- The extra square you add on
- Work it out= answer
The forth index rule using a hence question?
Hence= use the other question to help
What is the 6th index rule?
Combining rule 4 and 5!
Using the 6th index rule, what are the answers to theses:
- The minus in fraction means it’s 1/ number +power
- Change to a square root with no minus on the power
- Figure out the square root
Extra steps: (if needed)
1. Figure out the root ether cube or squared
2. Then figure out the power
Harder exam question using the 6th index rule?
Harder exam question:
1. Find a link between 32 and 16 to do with powers both in power of 2
2. Multiply powers and change the fraction to a number with a minus on the power
3. Powers are 5x=-4
4. X= -4/5
Area of a circle?
Area of a circle= π r²
What is the diameter and circumference of a circle?
Circumference= whole circle (2πr)
Diameter= x 2 radius
How to find the cumulative frequency?
- Use the frequency from the first diagram, the first one stays the same e.g 2 then the second one you add 2 and the next frequency number 6= 8
- Drawing the graph: always plot the end points (0<t<10) and the cumulative frequency number.
- The curve is a s shape all the time.
- You can find on the graph the Median (half) , Lower quartile (half of median), upper quartile (median+LQ) and interquartile range (UQ-LQ)
Using the graph to find a particular numbers of data? E.g Estimate the number of students who spent more than 42 minutes on their homework.
- Find 42 on the minutes axis
- Then draw up until you reach the line and draw across to the other axis
- Then read the value on that axis e.g 28, total pupils 30, 30-28=2
Answer= 2
Multiplying fractions?
multiplying numerators (top numbers) and denominators (bottom numbers) then simplify
. you can cancel before you multiply you can cancel any top number with any bottom number can be diagonal
Mixed numbers when Multiplying fractions?
- Turn the mixed number into a top heavy fraction (bottom number stays the same, then mixed numbers bottom number + top number= new top number)
- Check for cancellations
- Then multiply
- Change back into a mixed number (bottom number/ top= whole number, bottom stays the same, top number is what is left over from dividing to get the mixed number)
Multiplying decimals?
- Ignore decimal points the multiply the numbers
- Count the number of decimal places in question in both numbers then you will have same in the answer
- Check by rounding the question
Recurring decimals?
.Can be written with a dot on the numbers recurring, and if there is 3+ recurring numbers put a dot on first recurring number and on the end one to say all the ones in between also are recurring
Writing a recurring decimal as an exact fraction
.put a digit over the correct number of 9s, after you can simplify
How to prove a recurring decimal?
Proving recurring decimals
1. Say let x=the decimal
2. If it’s 1 recurring number you times by 10 if it’s 2 recurring numbers you times 100 ect…
3. You then subtract the 1st line from the second line
4. Turn into a fraction, simpfly if you can
Harder exam question recurring decimals?
.If you do all the steps and get a decimal you must multiply it out
What are prisms?
a solid geometric figure whose two ends are similar, equal, and parallel rectilinear figures, and whose sides are parallelograms.
(Not circular)
What is the volume of a prism?
A prism has the same cross section all the way through.
E.g cuboid, triangular prism
- Shade in the cross section
- Find the are of the cross section e.g triangle A= bxh/2
- Multiply the area by the length
Volume of a prism= cross section x length
Cuboids and cubes surface area?
- Area of each individual surface (draw dotted lines onto the shape)
- The sides are Rectangles: LxW
- Layout: Bottom, top, right, left, front, back
- Units: cm^2
Cuboids and cubes volume?
Volume of a cuboid:
Volume: length x width x height
Volume of a cube:
Volume= area^3
What is Direct proportional?
.Direct= as one increase the other also increase
What is inverse proportion?
.Inverse= as one increases the other decreases
What does it mean in exam if they say the word proportional?
If it says proportional= direct proportional
How to answer direct proportional questions?
- y ∝ x
- y=kx k= (constant)
- Swap the letters for the numbers given
- To figure out k (constant)
- Then you write an equation connecting y and x using y=kx then swap k for the figured out constant
Extra steps when it’s asks you find another value of a letter e.g find value y when x=8 - Substitute the the new value, then work out the value
How to answer a inversely proportional question?
- y ∝ 1/x
- y= k/x
- Swap the letters for the numbers given
- To figure out k (constant)
- Then you write an equation connecting y and x using y=k/x then swap k for the figured out constant
Extra steps when it’s asks you find another value of a letter e.g find value y when x=4 - Substitute the the new value, then work out the value
exam question on direct or inverse proportion?
exam question on direct or inverse proportion?
How to use a tree diagram?
(can be decimals or fractions)
1. Draw the options
2. Probability must add up to 1 so spilt between options (on each branch)
3. Then repeat the options
4. Then you can work out the probability, by going along a branch and multiplying
5. For the total probability is to add the two probability’s together
Tree diagram exam question?
(You can work out what happens if she wins both then take away from 1 to get probability of not winning both)
Harder tree diagram question?
Probability?
Using fractions:
Denominator= total options
Top number= chance of happening to a particular option
‘And’ ‘or’ probability questions?
Example of an ‘and’ question?
Exam question ‘And’ and ‘or’ questions mixed?
Hard probability ‘and’ and ‘or’ question?
- Work out the probability that they get the same
- Then take it away from 1 (total probability) answer if they not the same chocolate
What can you work out from a speed-time graph?
What can you work out from a velocity time graph:
1. Acceleration at any given time
2. Total distance travelled at any given time
How to find the acceleration?
.measured in= m/s^2
.horizontal= 0 acceleration (constant)
.Find Gradient (acceleration) m= change in y/change in x
How to find the total distance traveled?
Separate graph into shapes then find the area of each shape the add it up
Or
If it’s parallel (top and bottom line) you can use the formula for the area of a trapezium
Harder question: (non constant acceleration)? (Curved graph)
Estimate for acceraltion at a certain time:
1. Find the point
2. Draw a tangent (where the point is touched by a line but the rest isn’t)
3. Draw a right angled triangle using the line to find gradient
4. Work out the scale on graph
5. Find the gradient change in y/ change in x
(Hard question) Finding the average speed? (curved graph)
- Speed= distance/time
- Distance travelled under the graph (cut up Into shapes) (Trapezium parrel lines are a and b)
- Add up the areas
- Time is last number on the time axis
- The divided them Speed= distance/time
Worded question: speed time graphs (hard)?
(straight lines are constant)
1. Use the words to create a graph
2. Work out the areas of each shape then add them together
What is a Venn diagram and how do you figure on out?
.The people who has nothing go on the outside of the circle (the take away the people from total).
.to figure out who has both you add up the ones that say they have the items then take away away from the actual total of people = the ones that have both.
.to find who goes in the individual ones you minus the total you are told from the ones that have both.
(To check you add them up to check they match the total)
What are the notations used in Venn diagrams? (3)
Exam question on notation in Venn diagrams?
Probability using Venn diagrams?
(In probability you don’t need to cancel down fractions.)
Harder question on Venn diagram propbablitys?
Solving equations with fractions (method 1)?
You can multiply out the fractions
Solving equations with fractions (method 2)?
Multiply both sides by the fractions recipcaol e.g 2/3 (3/2)
Fractions of a number e.g 3/2 8 (8/2=4x3) divide by the bottom number times by the top
Solving equations with fractions with two fractions?
Multiply both sides by the common (same) denominator (use the least) to each thing the equation
Trigonometric values?
Negative numbers: Adding and subtracting?
.Two signs next to each other are different you take away
.two signs are the same you add
Negative numbers: Multiplication?
.two signs are different answer will be negative
.two signs are the same the answer will be positive
Negative numbers: one sign in the middle?
.C and d you swap around the numbers then add a minus on to the answer
How to Factories quadratics?
- Two brackets
- X^2= two xs in each bracket
- The second number, needs the two numbers in the brackets to add up to it
- The third number, need the two numbers in the brackets to multiply up to it
You can check my expanding it by doing the moon shape: the first bracket each thing in it multiplied by the other bracket
How to factories Negative coefficients?
- Start in the same way 2 brackets that both have an x in it.
- If it is minus when multiplying you need one minus
- If both are you still need one minus just make sure they add and multiply to the correct numbers
When do you use two minuses?
Sometimes you can make both minuses if you need a negative adding number but a positive multiplication number, because multiplying two minuses makes a positive but add to a minus.
How to solve quadratics?
The rights hand equals 0.
If you have two things that multiply to equal 0, then one of them is 0.
1. Put the equation out brackets (separate)
2. Then solve the linear equations, the answers will be the solutions
You can check by substituting each answers to the solutions.
How do you Solve when it’s not 0?
Make it equal zero by subtracting or adding it to both sides.
How Factorise difficult quadratics?
The the coefficient of x^2 is larger then
1. Take the coefficient of x^2 and multiply it by the end number in the equation (constant)
2. Then you have to find two numbers that multiply to make the answer to the first step and also need to add to make the middle number.
3. You the spilt the middle number into the answer to the second step also including x to each of the answers
4. Then put the first number and the last number next to the spilt number.
5. You then factorises (normally) the two terms each (two total)
6. You get the same bracket from the two factorisation, this is the first bracket of the factorisation of the difficult quadratic
7. The second bracket of the factorisation of the difficult quadratic, is from the left overs.
Larger number multiplication Factorising difficult quadratics?
Larger number multiplication: e.g 168 you half the number as you go up faster (1 and 168, 2 and 84)…
How to Solving quadratics with coefficient of x^2 ?
- Factorising as normal with quadratics coefficient of x^2, so you have brackets
- Then get rid of the brackets and just have the two linear equation that equal 0
- Then solve the two linear equations to find the two values of x (can be in fractions)
All the 4 different algebraic equations?
Formulae exam question?
Equations and expressions exam question?
You can check by putting the value of x into the diagram.
What are identities and how to show they are true?
You can’t move terms from one side of the equation to the other
To show it’s true: Make the left hand side look exactly like the right hand side
1. Simplify the left side, getting rid of brackets(expanding) and collecting alike terms
2. And do any thing else needed to make it the same e.g factorising