Posted by alia on Sunday, December 16, 2012 at 9:14pm.
*find the slope of y= 4/x +6
at the point (8,2)
*evaluate the derivative at the point (pi,4)
y=[tan(5x^8)]^3
please help

calculus  alia, Sunday, December 16, 2012 at 10:40pm
just tel me how to setup

calculus  Reiny, Sunday, December 16, 2012 at 10:48pm
I will assume your equation is as you typed it, and not
y = 4/(x+6)
y = 4/x + 6
= 4x^1 + 6
dy/dx = 4x^2
= 4/x^2
at (8,2) , dy/dx = 4/64 = 1/16
equation:
y2 = (1/16)(x  8)
16y  32 = x + 8
x + 16y = 40
y = [tan(5x^8)]^3
dy/dx = 3[tan(5x^8)]^2 (sec(5x^8) (40x^7)
at (π/4)
use your calculator to find the messy answer for dy/dx 
calculus  alia, Sunday, December 16, 2012 at 10:56pm
4/64
why 64 not 8 
calculus  Reiny, Sunday, December 16, 2012 at 11:06pm
notice dy/dx = 4/(x^2)
= 4/(8^2) = 4/64 or 1/16 
calculus  alia, Sunday, December 16, 2012 at 11:19pm
just plug pi/4
right 
calculus  alia, Sunday, December 16, 2012 at 11:30pm
thnks Reiny.