graphing square roots?

Question

how do i graph y=-9 square root of x?

Answer 1

y=-9sqrt(x), x=0 =>y=0, x=1=>y=-9 , x=4=>y=-18, x=9=>y=-27, x=16=>y=-36..........graphing the points (0,0), (1,-9), (4,-18) , (9,-27)..and goooo....

Answer 2

try plotting x in terms of y instead.
y = -9 * sqrt(x)
sqrt(x) = 1/9 * -y
now, we know we can't plot a square root that's negative.
So, left hand side (LHS) has to be +ive.
Hence, RHS has to be +ive
to do that, we've got only one choice: take -ive values of y.
Again, the sqrt(x) tells us we can only consider +ive values of x.
+x, -Y :: the graph lies in quadrant-4 (lower right)

And now, knowing our limits, we can square both sides.
y = -9 * sqrt(x)
y^2 = (-9)^2 * x
y^2 = 81x
x = 1/81 * y^2
this is in the form x = a*y^2, a parabola.
consider it like this: when y is 1, x is 1..
when y is 2, x is 4. So, x increases as square of y. The 1/81 simply flattens the curve a bit.

try searching for online grap-plotters; else download this good plotting (and maths all-in-1) software: GraphCalc

Answer 3

its a stretch of 9 in the y direction of the graph square root x which looks like a c, with the vertex going through the origin. U can sketch it from this. for more accuracy substitue values for x i.e. 1,2,3.... into the equation and plot with the corresponding y values.

Answer 4

Pay more attention in class.

http://search.yahoo.com/search?p=graph+y%3D9+square+root+x&fr=ush-ans

Answer 5

It should look like a parabola or hyperbola or something like that.