Pure Year 1 Flashcards
What is the cosine formula- both variations?
a^2 = b^2 + c^2 - 2bc x cos(A) Cos(A) = b^2 + c^2 - a^2 / 2bc
What is the sine formula- both variations?
sin (A) / a = sin (B) / b - angles
a / sin (A) = b / sin (B) - sides
What is pythagorasβ theorem?
a^2 + b^2 = c^2
What is a rational fraction?
A fraction with a surd in the denominator
What is 8^2/3?
4
Bottom number outside
Top number inside
How do you rationalise a surd?
Multiply by either the denominator itself if it is on its own or by itself & the opposite to either + or -
What is the quadratic formula?
x = -b +- root (b^2 - 4ac) / 2a
What is the discriminant and when does it show the number of roots a quadratic has?
b^2 - 4ac = 0 - 1 root (tangent if root repeated)
b^2 - 4ac > 0 - 2 roots
b2 - 4ac < 0 - no roots
How do you find points of intersection?
Equate the 2 equations
How do you write an inequality when the equation is greater than (>) ?
2 separate inequalities with the smaller one as less than ()
Because above the graph- opposite directions of solutions
How do you write an inequality when the equation is less than (
As one inequality because below the graph
What does the reciprocal graph y = 1 / x look like and where are itβs asymptotes?
Line in top right quadrant & bottom left quadrant with asymptotes at x = 0 & y = 0
What does the reciprocal graph y = -2 / x look like and where are itβs asymptotes?
Line in top left quadrant & bottom right quadrant with asymptotes at x = 0 & y = 0
What does the graph y = 2 / x^2 look like & where are itβs asymptotes?
Line in top left quadrant & top right quadrant with asymptotes at x = 0 & y = 0
What does the graph y = -5 / x^2 look like & where are itβs asymptotes?
Line in bottom left quadrant & bottom right quadrant with asymptotes at x = 0 & y = 0
In a function such as (a / b ) what direction does a & b control?
a controls left/right movements
b controls up/down movements
When a graph is translated, are its asymptotes translated with it?
When a graph is translated its asymptotes are translated with it
What does the translation y = -f(x) mean?
Reflection in the x-axis
What does the translation y = f(-x) mean?
Reflection in the y-axis
How do you calculate the gradient of the line between 2 points?
gradient = change in y / change in x gradient = y2 - y1 / x2 - x1
What is the product of the gradients of 2 perpendicular lines?
-1
What is unique about the gradients of 2 lines which are perpendicular to one another?
Their gradients are negative reciprocals of one another
What is unique about the gradients of 2 lines which are parallel to one another?
Their gradients are the same
How do you find the distance between 2 points?
Find the net coordinates by minusing them from one another and then use pythagorasβ theorem
Root {(x2 - x1)^2 + (y2 - y1)^2}
How do you calculate the mid point of 2 points?
Add each of the x & y coordinates separately and divide each one by 2 separately to form the midpoints coordinates
(x1 + x2/2, y1 + y2/2)
What is a perpendicular bisector and what is its gradient?
A line that passes directly in the middle of another line or 2 points and forms a 90 degree angle with that line or the line the 2 points form
Its the gradient of the negative reciprocal of the line it cuts or the line formed by the 2 points
What is the general equation of a circle?
x2 + y2 = r2
How do you find the gradient and radius of a circle when its equation is given in its expanded form? (x2 + y2 + 2fx + 2gy + c = 0)
Complete the square
What is unique about the tangent of a circle and its radius?
They touch only once and when they do they form a 90 degree angle
What is unique about the perpendicular bisector of a chord of a circle?
It will go through the centre of the circle
Define what the circumcircle of a triangle is
A circumcircle is a circle drawn using the 3 vertices of any triangle
Define what the circumcentre of a triangle is
It is the centre of the circumcircle and is the point where the perpendicular bisector of each side of the triangle intersect
What is different about the circumcircle of a right angled triangle?
The hypotenuse of the right angled triangle is the diameter of the circle because the angle in a semi circle is always a right angle
How do you find the centre of a circle when you have 3 points on its circumference
Join the points together to form 3 lines and find the perpendicular bisector of 2 of the lines. Find the midpoints of of the chords and plug into the perpendicular bisector equation to find C. Equate the 2 perpendicular bisector equations and the intersection found is the midpoint.
Define a theorem
Statement that has been proven
Define a conjecture
Statement that has yet to be proven