Mathematics
8 Online
OpenStudy (anonymous):
Find the equation of the line tangent to f(x) = 2/x-1 at the point (2, 2).
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
I found the derivative (x-1)^2
OpenStudy (anonymous):
I got the slope 1
OpenStudy (anonymous):
i used y-y1 = m(x-x1)
OpenStudy (anonymous):
I got
hartnn (hartnn):
(2/x) -1
or
2/(x-1)
?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
y=1x
OpenStudy (anonymous):
2/(x-1)
hartnn (hartnn):
then your derivative is incorrect.
OpenStudy (anonymous):
but the options I am given are. a)x+y+3=0
OpenStudy (anonymous):
b)x-y=4 , c) y-2= (x-2)/(x-1)^2, d) y=-2x+6
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
or e) none
OpenStudy (anonymous):
why? what did I do wrong?
hartnn (hartnn):
derivative of x^n = nx^(n-1)
so, derivative of 1/x is -1/x^2
hartnn (hartnn):
derivative of 2/(x-1)
= 2 derivative of (x-1)^(-1)
hartnn (hartnn):
what would be next step ?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
find the derivative? which is: - 1/(x-1)^2
hartnn (hartnn):
yes,
so the derivative is -2/(x-1)^2
OpenStudy (anonymous):
so now I insert the 2 in the x?
OpenStudy (anonymous):
hartnn quick question. is +infin. the same as infinity?
hartnn (hartnn):
yes, and yes
when we say infinity, its +infinity
when we want negative infinity, we must explicitly say -infinity
Join the QuestionCove community and study together with friends!
Sign Up
hartnn (hartnn):
tell me what slope you get when you put x=2
OpenStudy (anonymous):
-2/(2-1)^2
= -2/1
=-2
OpenStudy (anonymous):
thank you
hartnn (hartnn):
yes, you got the equation ?
OpenStudy (anonymous):
y-y1 = m(x-x1)
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
so
OpenStudy (anonymous):
y-2=-2(x-(-)2)
y-2 = -2(x+2)
y-2 = -2 x -4
y = -2x+6
hartnn (hartnn):
you are \(\huge \color{red}{\checkmark}\)
OpenStudy (anonymous):
thank you!!!!
hartnn (hartnn):
welcome ^_^