A tower with vertical walls stands on horizontal ground. A stone
is thrown from a window of the tower. At any instant, the
horizontal distance of the stone from the building is x metres and
the height of the stone above the ground is y metres, given by the
formula
y = 18 + 3x - x^2
The table below shows some values of x and the corresponding
values of y:
x 0
1 2
3 4 5
6
y 18 20 20
p 14 q 0
By drawing a suitable straight line on the graph, find the range
of values of x for which the horizontal distance of the stone from
the building is greater than the height of the stone above the
ground.
I analyzed the question for some time but then, is there anyway
i can draw a straight line? No gradient, nothing... the previous
parts of the question also did not ask me to draw any tangent,
etc.
Hi,
The first thing which you should do is to draw out y=18+3x-x^2.
After that sub in y = x into the equation and find the values of x.
Reject the negative value, and use the positive value ( let us take
it to be a ) to draw a line ( x=a ).
Hence, for all values of 6 >/= x > a, the
horizontal distance of the stone from the building is greater than
the height of the stone above the ground.
