Maths Flashcards
(18 cards)
What’s the equation for variance? Standard deviation?
https://www.savemyexams.com/a-level/maths_statistics/edexcel/18/revision-notes/2-data-presentation–interpretation/2-1-statistical-measures/2-1-3-standard-deviation–variance/
Equation for nCr?
nCr = n! / (r! * (n-r)!)
Equation of a circle
( x - h )^2 + ( y - k )^2 = r^2
Cosine rule for sides?
a 2 = b 2 + c 2 − 2 b c cos A
Cosine rule for angles?
cos A = (b2 + c2 - a2) / (2bc)
2 formulas to find gradient of the line?
y = mx + c
y – y1 = m(x – x1)
What do we use binomial PD for ?
CD ?
PD - e.g. p(x=6)
CD- e.g. p(x</= 6)
When do we use list ?
Variable?
List- if you don’t know what the value is
Variable- if you have set values
What assumptions do we make when using binomial distribution?
That there’s a fixed number of trials and fixed probabilities
Describe the effects the following objects have on the model:
- Particle
- Roughy surface
- Smooth surface
- Smooth pulley
- Light pulley
- Intextible string
- Rod
- Peg/support
- Rotational forces/ air resistance can be ignored. Assume that mass is concentrated at a point.
- Have friction to slow it down
- Does not experience friction so will carry on going until something else’s stops it
- Tension is the same in the string either side of the pulley
- Pulley has no mass
- String does not stretch under load which means that the acceleration is the same in any connected objects. If its light it means it will not affect the mass
- One dimension which is negligible like a pole or a beam. The mass is concentrated along a line, its rigid
- Support from which the body is suspended which means —> dimensionless, fixed. Can be smooth/rough
What’s the units for the following
1. Displacement
2. Velocity
3. Acceleration
4. Force/weight
5. Distance
6. Speed
7. Time
8.mass
- Metre
- Metres per second
- Metres per second squared
- Newton/g
- Metres
- Metres per second
- Seconds
- Kilogram
1.What is a rational number?
2.Irrational?
3. What’s a natural, real and integer? Symbols ?
1.Fraction or integer
2. A number that can’t be represented as a fraction
3. Natural numbers are counting numbers, real numbers are real( not imaginary) integers are whole numbers.
Integers- Z- All positive and negative whole numbers.
Natural- N- Numbers used for counting (all positive integers).
Real- R- Includes all numbers on the number line.
When drawing force diagrams, what do these mean?
1. R
2. P
3.F
4. W
- Normal reaction force
- The force pulling the object
- Resistance due to friction or air resistance
- Weight of object
- What is the lesson we need to take from Newton’s first law?
- What’s Newton’s second law?
- How to calculate weight?
- When using vectors what information so we know if they’re parallel?
- When an object isn’t accelerating the forces are equal/balanced in each direction
- F=ma where F and a are in the same direction
- W=mg where m= mass, g= gravitational pull ( 9.8 metres per second)
- They’re multiples of each other
- What would -f(x) do ?
- What would f(-x) do ?
- How to calculate are of trapezium?
- Reflection in x axis- changes y coordinates
- Reflection in y axis - changes x coordinates
- Area of a trapezium ——-> 𝑨=½ (𝒂 + 𝒃)𝒉
- What’s displacement ?
- Whats velocity?
- Key rules?
- SUVAT?
- Displacement - describes change in position of an object relative to a stationary point
- Rate of change of displacement ( how fast and in what direction)
• Velocity is the gradient of a displacement time graph
• Speed is the gradient of a distance time graph
• Velocity - V- m/s
• Displacement- S- m - • s – displacement (from the starting point)
• u – initial velocity
• v – final velocity
• a – acceleration
• t – time
In a reciprocal graph what can x not equal?
0
Displacement time graph vs velocity time graph :
Displacement time graph: gradient= velocity
Velocity time graph: gradient= acceleration
Velocity time graph : area under graph= displacement
