Maths Tips Flashcards
When dividing or multiplying by a negative
Flip the inequality
Finding the mean of new members
Set up two equations
Subtract original mean from new mean
Divide by number of additions
Rearranging
Don’t expand
Simultaneous equations
Try multiplying them up
Remember, if things are proportional you can keep k as
1
Remember scale factors
Length to volume is cubed
Let original
Original x 1.(profit) = price
Watch out for diameter
!!!
Always
Could be none of them
Binary fission
Not mitosis!
Genetically identical (barring mutations)
Chromosome replication in cytoplasm
Gametogenesis
Can be mitosis in plants
Observe n value
Fertilisation
Is not mitosis
Adult stem cells
Contain the same genes as somatic cells
As soon as you figure out x
Sub it in
Quadratic sequences
find second difference - half it for n2
Find difference between first sequence and the quadratic sequence multiplied by the second difference for integer term
Requirements for cells near the tip of the plant shoot to grow differently
Sufficient oxygen and glucose
Uneven distribution of plant hormone
Mutations
Can occur in gametes
Processes involved in dolly
Mitosis, meiosis and differentiations
Not genetic engineering
If given two coordinates
Sub in for simultaneous equations
How many numbers of copies of DNA sequence found
In human cells: 2
In bacteria cells: 1
In proteins: 0
X-acid and y-axis
Must be correct
Number of gas bubbles released per minute
Is not directly proportional
When u have h and r
Look for relationships
Is h 2r?
Dividing a number by a surd
Turn the number into a surd
If you see ‘less than’ or ‘greater than’
Set up an inequality
If it’s early on and ur really stuck with a triangle
Assume it’s right angled and use trig/Pythagorean’s
When you’ve found an algebraic gradient and Ur solving it in an inequality
Ignore the fact it’s a fraction and solve both lines as an inequality for the limits
Watch out for the inequality
If your answer has to be greater than/less than (NOT equal to) bear this is mind when choosing the smallest/largest possible value of something
Probability trees
Remember, are they replaced? Do they probabilities change each time?
Clock Q method
1) figure out what fraction the hour hand has made it though the hour, call this θ
2) θ x 30 = fraction
3) add this to the angle between the minute hand and the UB of the hour hand
If you have a surd over a fraction
Think about if there is something you can factor out of the top to show as a multiple
Finding bearings of legs of runs
1) The exterior is the angle by which the bearing changes each leg
2) find number of turns, multiply by exterior angle and subtract this from the first value
3) if you get a negative number, this is the anti-clockwise bearing
Change in y/ change in x
If you have a variable, don’t forget to put things in brackets
Bearings
Make sure you’re going from north
4 x 4
Is 16 not 8 u moron
If given a rhombus diagonals
Can assume half-distances to set up right hand triangles
If it’s already factorised?
Don’t immediately expand
Is there anything u can cancel
If the numbers are looking tricky
Look! Can you cancel?
Remember the difference between Co-ordinates and distance
Yep
Looking for similar shapes
Use θ1 and θ2
Remember total surface area
Have to use width, depth and height
If you have a triangle and area
Watch out! You might not have to make it into two right angled triangles if you already have the perpendicular height anyway
If there’s a ratio in the question
Make an equation and then make back into a ratio
Probability
Is it quicker to find the probability of the event NOT happening?
E.g. 1-P(X)
