pure Flashcards
new formula of a line
y-y₁ = m(x-x₁)
gradient of a straight line through 2 point
change in y / change in x
midpoint of a line
(x₁+x₂/2 , y₁+y₂/2)
quadratic formula
-b ∓ √b²-4ac / 2a
set notation for and inequality
{x: x> -3} ∩ {x: x<2}
set notation for or inequality
{x: x<-5} ∪ {x: x>1}
discriminant
b² - 4ac
discriminant when 2 different real roots
b² - 4ac > 0
discriminant when no real roots
b² - 4ac < 0
discriminant when 2 equal/repeated roots
b² - 4ac = 0
general form of a circle with centre (a, b)
(x-a)² + (y-b)² = r²
gradient of normal to a point on a circle
gradient from centre to radius
gradient of tangent to a point on a circle
negative reciprocal of normal gradient
the angle in a semicircle is…
a right angle
a line from the centre of a circle to a chord, at a right angle to that chord will…
bisect the chord and is the shortest distance from the chord to the centre
tangents from the circle to the same point outside the circle…
have the same length
(x+3) is a factor of 6x³-bx² + 18, find the value of b.
substitute x=-3
f(x) → -f(x)
reflection in x axis
f(x) → f(-x)
reflection in y axis
sine rule
a/sinA = b/sinB = c/sinC
cosine rule
a² = b² + c² - 2bc cosA
area of a triangle trig
0.5 × a × b × sinC
sin graph repetitions
- add 360
- 180 minus x
cos graph repetitions
- add 360
- minus x plus 360
tan graph repetitions
- plus 180
- minus 180
cos²x + sin²x
1
tan(x)
sin(x) / cos(x)
logₐa
1
logₐ1
0
logₐ(1/a)
-1
logₐx + logₐy
logₐ(xy)
logₐx - logₐy
logₐ(x/y)
logₐ(xⁿ)
nlogₐx
logₐ(aˣ)
x
general equation for exponential growth
V = Akᵗ
y = axⁿ
log(y) = log(a) + nlog(x)
y = kbˣ
log(y) = log(k) + xlog(b)
when to use (nCr)
(a+b)ⁿ
where n is a positive whole number
when to use n(n-1)/2!
(1+x)ⁿ
where n is a rational number
differentiate eⁿˣ
neⁿˣ