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View Full Version : Find equation of line tangent to graph f(x) = (lnx) at x =4


bvanden43
Jun 29, 2010, 04:14 PM
find equation of the line tangent to the graph of f(x) = (lnx)^6 at x = 4

galactus
Jun 29, 2010, 04:46 PM
The equation of the tangent line is

y=f'(x)(x-4)+f(x)

Plug it all in. Let x=4

f'(x)=\frac{6(ln(x))^{5}}{x}