auto ad

Showing posts with label applications. Show all posts
Showing posts with label applications. Show all posts

Monday, January 19, 2009

equation of tangent

find the equation for the tangent to y = x^4 at the point where x=2
first substitute x=2 into the given equation to find y to get the point (x1,y1)
at which the tangent is required.
find dy/dx and evaluate it at (x1,y1) to get the slope,m of the tangent
then use (y-y1) = m(x-x1) to get the equation of the tangent

-----------------------------------------------------------
please leave your comments below
------------------------------------------------------------
index of math problems


disclaimer:
There is no guarantee about the data/information on this site. You use the data/information at your own risk. You use the advertisements displayed on this page at your own risk.We are not responsible for the content of external internet sites. Some of the links may not work








Monday, September 29, 2008

orthogonal trajectory of y = (k/x)

find the orthogonal trajectory of y = (k/x)

first we find the diff. equation of the given family
y=(k/x) -----------(1)
diff. w.r.t. x
y' = -k / (x²)---------(2)

eliminating k , divide (2) by (1)

y' / y = -1/x ---------(3)

(3) is the diff. equation of the given family.
replace y with -1/y' in (3) to get the diff. equation of the orthogonal trajectory

diff. equation of the orthogonal trajectory is

-yy' = -1/x
y(dy/dx) = 1/x

ydy =xdx
integrating and simplifying, we see that the orthogonal trajectory is

x² - y² = C


disclaimer:
There is no guarantee about the data/information on this site. You use the data/information at your own risk. You use the advertisements displayed on this page at your own risk.