Unit 1 Flashcards
What is the discriminant?
b² - 4ac
Two distinct real roots?
b² - 4ac > 0
Two real roots?
b² - 4ac => 0
One real root?
b² - 4ac = 0
No roots?
b² - 4ac < 0
What is remainder theorum?
When f(x) is divided by the polynomial x - a, the remainder of the calculation is f(a)
What is factor theorum?
If f(a) = 0 then x - a is a factor of the f(x)
What are the types of proof?
- proof by deduction
- proof by exhaustion
- disproof by counter example
What is the length of a line?
√(x2 - x1)² + (y2 - y1)²
What are the two equations for lines?
y = mx + c
y - y1 = m(x - x1)
What is the midpoint of a line?
(y1 + y2 / 2, x1 + x2 / 2)
What is the gradient of a line?
y2 - y1 / x2 - x1
What is the sine rule?
a/sinA = b/sinB = c/sinC or vice versa
What is the cosine rule?
a² = b² + c² - 2bccosA
or cosA = b² + c² - a² / 2bc
What is the area of a triangle?
1/2 ab sinC
What are the circle theorems?
- the angle in a semi circle is a right angle
- the perpendicular from the centre to a chord bisects the chord
- the radius of a circle at a given point on its circumference is perpendicular to the tangent to the circle at that point
What are the trig identities?
sin²θ + cos²θ = 1
sin²θ = 1 - cos²θ
tanθ = sinθ/cosθ
What is the symbol for “is a member of”?
A big curved E
What are the symbols for the set of all integers and the set of all positive integers?
A big Z and a big Z with a +
What is the symbol for the set of all real numbers?
A big R
What does it mean when numbers are in curly brackets?
That all the numbers within it are included e.g. {1,2,3,4,5} 1, 2, 3, 4 and 5 are all included.
What does it mean when numbers are in square brackets?
That the numbers from the first number to the second number are included, including the first and second number e.g. [1,5] numbers 1-5 are included as well as 1 and 5.
What does it mean when numbers are in regular brackets?
That the numbers from the first number to the second number are included, NOT including the first and second number e.g. (1,5) numbers 1-5 are included MINUS 1 and 5.
What are the log laws?
- log(xy) = log(x) + log(y)
- log(x/y) = log(x) - log(y)
- nlog(x) = log(x^n)