Question

Does anyone know how to do completing the square?

Answer 1

You have have ax^2 + bx + c = 0
Or rearrange to get that
Then divide by to have just x^2
Now you have x^2 + dx + e = 0
Add and subtract the same value to the left hand side in order to have enough
to do
(x + f)^2
where 2f = d
Hope that makes sense.

Answer 2

http://en.wikipedia.org/wiki/Completing_the_square

Answer 3

yes

Answer 4

Ok. I know how to that but im having trouble with ones like x^2-18x+57=60

Answer 5

see the number in front of the "x" part?

Answer 6

Yes

Answer 7

we want to add zero to this thing so that the value remains the same; so add and subtract the square of half that "x" number to it

Answer 8

What you want there is (x-9)^2
because that will give -18x
Now we just have to fix the rest.

Answer 9

OK that much i can do its just after the equal sign its a number and its usually a zero

Answer 10

subtract 60 from both sides then ...

Answer 11

spose you have a set of scales; such that the left sides equals (or balances) with the right side.

in order to keep all things equal, whatever you do to one side has to be done to the other

Answer 12

since you want zero on the right, subtract 60 from the 60 that is there; and do the same to the other side to keep things balanced

Answer 13

Ok I am understand now just sub 60 and just solve like completing the square

Answer 14

x^2-18x+57=60
-60 -60
----------------
x^2-18x -3 = 0

yes

Answer 15

Omg.. Thanks now im understand

Answer 16

youre welcome :)

Answer 17

Now my last question do you know how to solve this problem.. A circle has a radius of 3 units and a center (1,-2). Find the equation of the tangent line at the point (5,-2). write the equation in slope intercept form

Answer 18

the tangent of a circle at a point in its rim uses the perp of the slope from center to point

Answer 19

then use the rim point in the point slope setup to manipulate it into the slope intercept form

Answer 20

or to draw it out more according to the pointage :)