a landscape architect wants to position a tree 2 meters east and 3 meters south of a stone marker in a garden.?
July 6, 2009 by Builder Wong
Filed under Garden & Landscape
when a tree is full grown, a branches will be rounded off round with a hole of about 3 meters. write an equation representing a outward of a grown tree’s branches relations to a stone
A- (x+3)^2 + (y-2)^2 = 9
B- (x-2)^2 + (y+3)^2 = 2.25
C- (x+3)^2 + (y-2)^2 = 2.25
D- (X-2)^2 + (y+3)^2 =9
HELP
taking E as the +ve direction of the x-axis
and N as the +ve direction of the y-axis,
the center of the circle is (2, -3) & the radius is 1.5 m
so the appropriate equation is
(x-2)^2 + (y- (-3))^2 = (1.5)^2
i.e. (x-2)^2 + (y+3)^2 = 2.25
ANS : [B]
So a circle has the equation
(x – h)^2 + (y-k)^2 = r^2
The diameter is 3m
The radius is 3/2m
so
(x – h)^2 + (y-k)^2 = (3/2)^2
(x – h)^2 + (y-k)^2 = 2.25
Now (h,k) is the centre of the circle i.e. 3
2 m east would mean
h = 2 units right on the x axis
k = -3 units up on the y axis
(x – 2)^2 + (y – - 3)^2 = 2.25
(x – 2)^2 + (y + 3)^2 = 2.25
The Answer is B