Name: senthil
Question:
sir,
between line and curve how can i
find intersection point?
could you write me the formula and explanation also sir.
thanking you
Hi Senthil,
Lets do it with an example. Suppose that you have the line
y = 2x + 3
and the curve
y = x^{2} + 3x + 1
and you want to find any intersection points. What I see in my mind is a curve and a line that intersect, as in the diagram below, where (a,b) is the point of intersection.
Since (a,b) is on both graphs, the line and the curve, is satisfies both equations. That is
b = 2a + 3
and
b = a^{2} + 3a + 1
Thus
a^{2} + 3a + 1 = b = 2a + 3
Thus if you solve
a^{2} + 3a + 1 = 2a + 3
for a you will find the xcoordinates of any points of intersection. Simplifying this equation I get
a^{2} + a  2 = 0
which I can factor as
(a  1)(a + 2) = 0
and thus a = 1 or a = 2.
If you now substitute these values for x into either either equation you will find the ycoordinates of the two points of intersection.
I hope this helps,
Penny
