# In which choice do all three points lie on thesame straight line?A А.(0, 1), (-1, 3), (1, 3)B.(4, 2), (2, 1), (4, -2)C (0,

###### Question:

A А.

(0, 1), (-1, 3), (1, 3)

B.

(4, 2), (2, 1), (4, -2)

C (0, 0), (8, 0), (0, 8)

D

(1, 2), (2, 4), (4,8)

## Answers

D (1, 2), (2, 4), (4,8)

Step-by-step explanation:

Points lying on the same line:

If three points lie on the same line, the change in y has to be always the same when x changes by 1.

А. (0, 1), (-1, 3), (1, 3)

(-1,3) to (0,1): x changes by 1, y by -2

(0,1) to (1,3): x changes by 1, y by 2

So these points are not on the same line.

B. (4, 2), (2, 1), (4, -2)

Two values for y when x = 4, so not on the same straight line.

C (0, 0), (8, 0), (0, 8)

Two values for y when x = 0, so not on the same straight line.

D (1, 2), (2, 4), (4,8)

Here, when x changed by 1(from 1 to 2), y changed by 2.

When x changed by 2(from 2 to 4), y changed by 2*2 = 4.

So these points are on a straight line, and D is the correct answer.

if the eqn of the parabola is f(x) = (x-4)(x+2), we need to mult. this out to find the coordinates of the vertex.

then f(x) = x^2 + 2x - 4x - 8, and f(x) = x^2 - 2x - 8.

one way in which you can find the vertex is to calculate x = -b / (2a). here, that comes to

)

x = = 1. f(1) = 1^2 - 2(1) - 8 = - 9. vertex is at (1, -9).

2(1)

find another point on the curve: let x=0, for which y=-8. then (0, -8) is on the curve. plot the vertex and this point and draw a smooth parabola thru both.

hope this

[tex]Use the parabola tool to graph the quadratic function f(x)=(x-5)^2+1 graph the parabola by first plo[/tex]a) $ 9.50

b) 17

c) y-intercept (0, 12). this is the initial amount of money that joe had prior to playing any game.

d) x-intercept ( 24, 0). this is the number of games that joe will play before he depletes the initial amount of money that he had.

e) slope is -0.5. joe's balance will reduce by 0.5 for every game that he plays.

f)

domain; [0,24]

range; [0,12]

g) x + 2y = 24

step-by-step explanation:

a)

if joe plays 5 games, this will imply that x = 5. substitute x = 5 in the equation and solve for y;

y = -.50x + 12

y = -0.50(5) + 12

y = 9.50

b)

if joe leaves the arcade with $3.50, this will mean that y = 3.50. plug in y = 3.50 in the given equation and solve for x;

y = -.50x + 12

3.50 = -0.50x + 12

0.50x = 12 - 3.50

0.5x = 8.5

x = 17

c)

the function given is y = -.50x + 12.

the y-intercept is the point where the graph of this function will intersect the y-axis. at this point, the value of x is usually 0. plug in x = 0 in the given equation and determine y;

y = -0.50(0) + 12

y = 12

the y-intercept is thus (0, 12). this is the initial amount of money that joe had prior to playing any game.

d)

the x-intercept refers to the point where the graph of a function intersects with the x-axis. at this point, the value of y is 0. substitute y = 0 in the given equation and solve for x;

0 = -.50x + 12

0.5x = 12

x = 24

x-intercept ( 24, 0). this is the number of games that joe will play before he depletes the initial amount of money that he had.

e)

the slope of the given equation is -0.5. the equation has been given in slope-intercept form. thus the slope is simply the coefficient of x.

joe's balance will reduce by 0.5 for every game that he plays. this is the interpretation of the slope.

f)

domain is the set of x values for which the function is real and defined. the domain will thus be; [0,24]. this will restrict the balance to only assume positive values.

on the other hand, the range is the set of y values for which a function is real and defined. the range in our case will be [0,12]. joe can have between $0 and $12 balance.

g)

the standard form of the equation of a straight line is;

ax + by = c

where a, b, and c are integers.

our equation is given as;

y = -.50x + 12

re-writing the equation we have;

0.5x + y = 12

divide all through by 0.5;

x + 2y = 24