Question

Part 1: Solve each of the quadratic equations below. Show your work. (3 points)

x^2 – 36 = 0 and x^2 = 8x – 12

Part 2: Describe what the solution(s) represent to the graph of each. (2 points)

Part 3: How are the graphs alike? How are they different? (2 points)

Answer 1

Is the formula to these -b +- (sqrt) b^2 - 4ac / 2a?

Answer 2

\[x^2 - 36 = 0=====> (x -6)(x+6) = 0\]

x = 6 or -6

number 2

rewrite the equation

x^2 - 8x + 12 = 0

this also factorises

(x - 6)(x - 2) = 0

the solutions are x =6 and x = 2

Answer 3

@careless850 you can use that formula too

Answer 4

the solutions to the equations are where the graphs cut the x -axis

y = x^2 - 36 cuts the x-axis at -6, 6 is symmetric about the y axis has a y intercept of y = 36 and is concave up.

y x^2 - 8x + 12 cuts the x=axis at x = 2 and 6 , is concave up, has a line of symmetry of x = 4 cuts the y axis at y =12 and has a minimum value of y = -4

Answer 5

So confusing dude...

Answer 6

in which part

Answer 7

Is there a formula I can use?

Answer 8

A simple algebraic formula..

Answer 9

since you know the quadratic formula you can apply it in x^2 - 36

a = 1; b= 0; c = -36

\[\LARGE x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\] \[\LARGE x = \frac{ 0^2 \pm \sqrt{0^2 - 4(1)(-36)}}{2(1)}\] got that?

Answer 10

you can use

\[x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\]

just identify a b and c in each equation

Answer 11

there is no simple algebra formula for solving quadratics...

factorising or using the formula shown by labasallote

Answer 12

That one

Answer 13

You just did.

Answer 14

well thats the only one...

but you need to remember you need evaluate the formula fully if the examiners are looking for solutions

Answer 15

Okay so can we try the first one with that formula? step by step?

Answer 16

ok.... what is a= b= and c =

Answer 17

a is 1 b is 1 and c is -36.

Answer 18

there is no b in x^2 - 36... only a and c

Answer 19

or more correctly b = 0

Answer 20

Alright.

Answer 21

So, a is 1 b is 0 and c is -36.

Answer 22

yes... good start

Answer 23

Now what do I do from here?

Answer 24

substitute them into the formula

write it on the drawing pad