equation of the tangent line

Find the equation of the tangent line to the following curve at the given point *P*. Illustrate by graphing the curve and the tangent line on the same screen. http://www.webassign.net/cgi-bin/sym...%20sqrt%28x%29

http://www.webassign.net/cgi-bin/sym...1%2C%204%5C%29

http://www.webassign.net/cgi-bin/sym...xpr=y%20%3D%20 1

http://www.webassign.net/cgi-bin/pal...E%3C%2Fmath%3E http://www.webassign.net/wastatic/common/img/cross.png

what did I do wrong? :( please help! (Headbang)

Here are the steps:

I did it according to this Find the equation of the tangent line to the following curve at the given point P. ? - Yahoo! Answers

y`=6-2x^(1/2)

6-2(1)^(1/2)

y`=4

y-4=4(x-1)

y-4=4x-4

y`=4x (and it's WRONG T_T)

please help me thanks you!!! (Crying)