Thread: sketching a graph

how can i sketch x^2+y^2-16x+8y+16=0

can you give me please try to explain the steps that i need to do


thanks

Originally Posted by Candy101

how can i sketch x^2+y^2-16x+8y+16=0

can you give me please try to explain the steps that i need to do


thanks

it's a circle ... complete the square for both x and y and get it into the form



(h,k) is the center ... r is the radius

Originally Posted by Candy101

how can i sketch x^2+y^2-16x+8y+16=0

can you give me please try to explain the steps that i need to do


thanks

this is a circle that needs to be put in standard form to easily sketch it. I was able to realize that since the coefficients of the and are the same, namely =1

We must complete the square for both x and y, so we divide the coefficient of the x and y terms by 2, square them, and add them to both sides



And now we can factor



Can you sketch that now or do you need further assistance?

i dont really know how to sketch it...

(x - 8)^2 + (y + 4)^2 = 64 = 8^2

compare it with the standard equation of a circle, that is

(x - h)^2 + (y + 4)^2 = r^2,

h,k is the CORDINATE of the center of the CIRCLE, where r is the radius.

from (x - 8)^2 + (y + 4)^2 = 64 = 8^2; center coordinate is (h,k) is (8,-4) and r = 8.

see the graph . . . .



if the standard equation of the circle awe you, resort to point plotting, maybe you have not encounter yet ANALYTIC GEOMETRY.


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