What is the name of a line that runs all the way through a circle and continues through it?
A secant line
What is the solution to: sketch the graph of a>0, b<0 where y=ax+b
a>0 so ‘a’ is a positive integer, thus the gradient is positive
b<0 so ‘b’ is a negative integer, thus the y-intercept is negative
(Answer is any graph that fits these conditions)
When y=k(x-a)^2 what effect does ‘k’ have on the roots?
No effect
What effect does the ‘2’ have on the roots for this equation:
y = 2(4x-3)(8x+1) ?
No effect
What’s the value of root 2 as a power of 8?
8^1/6
What is the value of 1/(x^-1) ?
x
What is the fewest number of real roots a cubic graph can have?
1
Can a cubic graph have 2 roots?
Yes, it can have a repeated root at one point (where the graph has a turning point there) and another root somewhere else
How do you name the quadrants in a graph?
1 is the top right quadrant, the others are named up to 4 in a clockwise direction
When mapping y=x^3 onto y=-x^3 what is the transformation?
Reflection in the x-axis
In y = 1/8(2-x)(3-x) what effect does 1/8 have on the gradient of the graph?
The gradient becomes shallower
In y = -(x+3)(x-2) what effect does the minus sign have on the roots?
No effect it only refers to the orientation of the graph (-x^3 shape rather than x^3)
How do you describe the mapping of y = 1/x onto y = (2/x) -3 ?
A stretch parallel to the y-axis first (represented by the 2) then a translation of the graph by the vector zero, -3
Simplify y = (x+5) / (x+3)
y = (x+3)+2 / (x+3) = 1 + (2 / (x+3))
What does the domain of a graph refer to
The set of all possible input values of x for which the function is defined. (To find it, look at the graph’s horizontal extent—from the furthest left point to the furthest right point—to see which x values are covered)
What is the range of a graph?
The set of all possible y-values it covers, from its lowest to its highest point. (To find the range, you look at the graph vertically, scanning from the bottom of the graph upwards to determine the minimum and maximum y-values the function reaches.)
How is y=1/x mapped onto y=-1/x ?
A reflection in the x-axis
How is y=1/x mapped onto y=1/-x ?
A reflection in the y-axis
Use polynomial division to turn y = (2x-3) / (x+4) into a form that can be plotted onto a graph more easily
2 + (a remainder of ) 11 / (x+4) is the answer
Simplify y = (3x+1) / x
(3x/x) + (1/x) = 3 + 1/x
What does the 2 in y=2/x do to the shape of the graph compared to y=1/x ?
Causes a stretch by scale factor 2 parallel to the y-axis (the curve of the graph gets further away from the intersection of the asymptotes!!)
What is the transformation mapping y=x^2 onto y+3=((x+1)^2)-9
y=x^2 mapped onto y=((x+1)^2)-12 is a translation by the vector [-1,-12]
How is y=log(x) mapped onto y=log((x+2)/1000) ?
log((x+2)/1000) is the same as log(x+2) - 3 so it’s a translation by the vector [-2,-3]
Write the equation of the image of y=x^2+6x after a translation by vector [-2,3]
y=(x+2)^2+6(x+2)+3