Find the equation of the tangent line to the curve at the given point.
y = 9x − 8sqrtx (1, 1)

Question

Find the equation of the tangent line to the curve at the given point.
y = 9x − 8sqrtx   (1, 1)

tkhunny · Answer

Find the 1st Derivative.

y' = ???

anonymous · Answer

If I did it right, I got 
9-4x ^{-1/2}

tkhunny · Answer

Well, don't forget to write the entire equation or definition.  It will keep you from becoming confused.

y' = 9 - 4/sqrt{x}

That is correct.  Now, just evaluate it at x = 1 and you have your slope.

anonymous · Answer

m=5?

tkhunny · Answer

That's it.  It's Point-Slope Time!  Let's see the equation of the line.

anonymous · Answer

y-1=5(x-1)
so, 
y=5x-4

tkhunny · Answer

Done.  You're a pro.

anonymous · Answer

Thanks again! I think I was just over analyzing. I have literally worked out all 8 of my homework's and have made a list of questions just to put on here!