Forgottone Knowldege

Question 1

What does the discriminate b2 -4ac tell you

Answer 1

If 0 = one real
If above 2 real

If below then none

Question 2

Damn if it says ALTEAST ONE then it means either one OR TWO thus it’s a greater than = to sign!

Can loose easy marks like this

Question 3

Remember dividing by - sign for inequalities?

Answer 3

Flip the sign

Question 4

Two lines are parallel vs perpendicularly about grsdienrs

Answer 4

Same vs -1

Question 5

Remember circled thst when a chord bisected it always goes through the

Answer 5

Radius

Thus 3 points ti find equation find the equation if the line of the visecotrs if bith and equate will give you the coordinated and then it should be easy

Question 6

Things about the sun and case graphs

Answer 6

Sin has rotational symmetry about origin so that sin 10 = x is same as sin-10 =-x

Cos has symmetry abkut origin so that cos 90 = cos-90

Sin also has some too lol

Tan also has rotational symmetry, sin and tan

Question 7

So why can’t sometimes you divide by say cos theta or sin theta

But when can you?

Answer 7

Because in case they might be 0, ofc yiu csn’t divide by 0 as that’s not possible

Say you want to divide by cos0 check what happens if it is 0

If cos theta is 0, the. See if sin theta has to be 0. If it is, then yiu can divide because this means cos theta can’t be 0 as sin theta can’t be 0 too for the same values of

Thus you can divide! And make tan and continue

Question 8

For trig try to factorise first and be wary of dividing by cos0 (0) not actually multiplying

Question 9

Remember square rooting in trig thingd gives you plus - so way more solutions

Question 10

Remember even if you factorise and have anither solution, always check first if thst can even be 0. If it can then go ahead if not then ignore!

Question 11

Remember for the ambiguous case and see if the other is a solution too

What happens if other is a solution

Answer 11

This is importsnt , write bith of them down!

Question 12

What is cosine rule bruv

Answer 12

A2= b2 + c2 -2bc CosA

Question 13

Area of a triangle

Answer 13

1/2ab sin c, works for ANY TRIANGLE

Question 14

If it’s cos 2x, then it repeats every 180 now (remember all x values oppsite), so have to say + 180 etc

Question 15

Remember if they give sin theta then yiu can use solid values in the identities, get values for cos theta and tan without even knowing what theta is

Question 16

If they gave you a graoh especially in jnequakities it’s for a reason, make sure to use it to answer final psrt of question stuck on

Question 17

Polynomials
How to add and subtract

Answer 17

Just do that normally

Question 18

Rules for graphs of polynomials (roots and turning points )

Answer 18

At most it has n amount of roots if it is degree n

And n-1 turning points if it’s degree n

(Rest if the roots are complex )

Question 19

Quartier shapes

Answer 19

These are W and m or just close together

Question 20

Sketching a graoh what do you need
Amd if one root is x what will y be always!

Answer 20

All intersections with axis INCLUDING Y

If one root is x y will have to be 0 too!

Question 21

Factor theorem

What will this usually be?

Answer 21

If f (2) = 0, then x-2 a factor

Etc

A factor of thr k constant

Question 22

When factorising make sure ti show discriminate is less than 0 or something ti show it can’t be factorised anymore, use cal first to check then do

Question 23

Remmeber there is normally a constant a at the start of every polynomial, so if the y intercept isn’t matching thstswhy

Also what should you just do Esch time

Answer 23

Put in Calculator it’s easier