- #1
studentxlol
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Homework Statement
Find the equation of the normal to the curve y=(6x+3)^(1/2) at the point for which x=13.
Homework Equations
dy/dx=dy/du*du/dx
y-y1=m(x-x1)
The Attempt at a Solution
y=(6x+3)^(1/2)
dy/dx=1/3(6x+3)^2
gradient of normal = -3(6x+3)^2
at x=13, dy/dx=-3(6x13+3)^2=19683.
obviously a silly answer and the textbook disagrees.
So at this point I could simplify y=(6x+3)^(1/2) to y=(2x+1)^2 maybe? Even after doing this, I end up with an even slightly smaller silly answer and the textbook still disagrees, unless the textbook is wrong, although this is highly unlikely.
HELP!