# math

posted by Robert

factorise 1-16(1-y)^2

1. Reiny

difference of squares

= (1 + 4(1-y) )(1- 4(1-y))
= (1 + 4 - 4y)(1-4 + 4y)
= (5-4y)(4y - 3)

2. Bobby

I am very good at maths, I am estimated to get an A+, but I hate turning point questions.

How do you find the turning point when given the quadratic function?

f(x)=(x+3)^2 - 16
Write down the co-ordinates of the turning point on the grap of y=f(x)

3. Robert

given a GP below, find the values of m, and the next 2 terms:
m, m+3, m^2+3

4. Reiny

For a quadratic function , the turning point would be the vertex of the parabola.
since your equation is written in vertex form
f(x) = (x+3)^2 - 16
the vertex is (-3,-16) , which would be your turning point.

f(x) = ax^2 + bx + c
there is a quick way to find the vertex
the x of the vertex is -b/(2a)
once you have that x, sub it into the equation to get the y
e.g.
y = 3x^2 + 9x - 11
the x of the vertex is -9/6 = -3/2
then y = 3(9/4) + 9(-3/2) - 11
= 24/4 - 54/4 - 44/4
= -37/2
the vertex or turning point is (-3/2 , -37/2)

5. Reiny

if m , m+3, m^2 + 3 are in geometric progression, then

(m+3)/m = (m^2 + 3)/(m+3)
m^3 + 3m = m^2 + 6m + 9
m^3 - m^2 - 3m - 9 = 0

normally cubics are hard to solve, but I tried factors of 9
and found m = 3 to work

so the numbers are 3, 6, 12
so each number is double its previous one, r = 2
the next 2 numbers are 24 , 48

## Similar Questions

1. ### factorising

how do you factorise? for example putting 2x² + x - 3 into the form (2x + 3)(x - 1) factorise 9x to the power of 4 - 64y to the power of 2
2. ### math

help my daughter has a math problem and came to me for help, I am lost.... what is the gcf for the following trinomial?
3. ### math

factorise 1. 3a^2 - 2a - 8 2. 3x^2 + 31 + 10 3. 64y^2 - 49 please help thankyou
4. ### math

factorise 7x^2 - 19x + 10 13x - 20 - 2x^2 28n - 10 + 6n^2 please can you show me the method thanks
5. ### Maths

How to do factorise ? What is Factorise ?