Unit 2 Flashcards
How do you find the roots of a quadratic
Factorise
Complete the square
Use quadratic formula
What is the quadratic formula
x = -b +- √b²-4ac
2a
What is the discriminant formula
b²-4ac
If b²-4ac>0…
The roots are real and unequal/distinct
If b²-4ac=0…
The roots are real and equal/repeated root
If b²-4ac<0…
There are no real roots
y=a(x+p)²+q
How to extract axis of symmetry
x=-p
y=a(x+p)²+q
How to extract turning point
(-p,q)
How to determine how many roots a parabola has
Use discriminant formula
b²-4ac
How to sketch a parabola with one or two roots
Factorise or use quadratic formula to find x axis intercepts
Use x=0 to find y axis intercepts
Find turning point, halfway in between x coordinates
How to sketch a parabola with no real roots
Find y axis intercept with x=0
Find turning point by completing the square
Formula for the equation of a parabola
y=k(x-a)(x-b)
How to find the equation of a parabola
Sub in x coordinates to a&b in equation
Sub in y coordinates
Rearrange to find k
Write out equation
How to solve a quadratic inequality
State whether concave up or down
Factorise to find where cuts the x axis
Draw graph to find where x is on parabola
State values of x
How to find the point of contact of a tangent
Make equations equal
Rearrange
Factorise for x value
Sub x value into equation of line
How to find points of intersection of curves
Make equations equal
Factorise for x coordinates
Sub into equation of line for y coordinates