Quadratic Functions Flashcards
Types of quadratics
1) monic- coefficient of x^2 = 1
2) non monic- coefficient of x^2 is not 1
Solving quad equations
1) factorisation
2) completing the square
3) quadratic formula
Solving quad inequalities graphically
1) f(x)>0 ABOVE
2) f(x)=0 ON
3) f(x)<0 BELOW
The discriminant
1) if
- –> NO REAL ROOTS
- > pos definite a>0
- > neg definite a<0
2) If
—> 2 EQUAL ROOTS
3) if
- –> 2 UNEQUAL ROOTS
- > rational ->
If ax^2+bx+c is congruent to Ax^2+Bx+C
Then:
A=a B=b C=c *HINT 1) expand one expression then rearrange it in the form of the alternative expression 2) solve simultaneously
Sum of roots where A and B are roots
A+B= -b/a
Product of roots where A and B are roots
AB= c/a
Roots special result where A and B are roots
A^2 + B^2 = (A+B)^2 -2AB
The Discriminant and POIs
If we are asked to determine whether a quad function and an SLG have POIs, we must:
1) set up a simultaneous equation
2) rearrange the simultaneous equation so that we get a quadratic equation
3) using the quad equation, find