General Revision Flashcards
(14 cards)
What is compound interest?
Compound interest is the interest that is added to the original total over a certain period of time.
What would you type in the calculator to work this out?
Compound interest: Invest £2000 for 3 years at a rate of 12.5%
2000 x 1.125³
What is depreciation?
Depreciation is when a value decreases.
What would you type into a calculator to work this out?
Work out the latest cost: A car costs £5000 and depreciates by 7.3% for 4 years?
5000 x 0.927^4
What would you type into a calculator to work this out?
A coat costs £45 after a reduction of 7%. What was the original price?
45 / 0.93 = £48.15
What would you type into the calculator to work this out?
A slug weighs 8 grams after an increase of 42%. What was the original weight?
8 / 1.42 = 5.63
How do you work out reverse percentages?
Get the percentage of the original number. If the percentage is an increase then add it to 100, if it is a decrease then subtract it from 100.
Then, multiply the final number by 100.
Divide this number by the percentage (divide the amount by the multiplier)
What is standard form?
It is a useful way of writing down very large and small numbers in a easy form. You write it as a (which is a number higher than 10) x 10^n.
What do we need to remember about upper and lower bonds?
- 999999… is the same as 1
0. 499999… is the same as 0.5
If you know tan(x) = 3.54, how would you work out x?
Tan⁻¹(3.54)
What is the quadratic formula??
x² = -b±√b²- 4ac
——————
2a
What does the ± symbol mean in the quadratic formula?
There are two calculations to do, with + and -
How can you check your answers to the quadratic form are correct?
You substitute your numbers into ax²+bx+c=0 to see if it is correct or back into the original equation.
When you label a trapezium, what are a, b and h?
a and b= are parallel lines
h= perpendicular height
