What is the equation of the normal line of f(x)=1/(1-2e^(3x)f(x)=112e3x at x=0x=0?

1 Answer
Jan 20, 2017

x+6y+6=0x+6y+6=0. See the normal-inclusive Socratic graph.

Explanation:

graph{(y(1-2e^(3x))-1)(x+6y+6)(x^2+(y+1)^2-.04)=0 [-10, 10, -5, 5]}

The foot of the normal is ( as marked in the graph ) is P(0, -1)P(0,1).

f(1-2e^(3x))-1f(12e3x)1. So,

f'(1-2e^(3x))-6ye^(3x)=0#,

giving f' xx (-1)-6(-1)=0 to f' = 6, at x = 0.

So, the slope of the normal is #-1/f'=-1/6, and so, its equation is

y-(-1)=-1/6(x-0), giving

x + 6y + 6 = 0.

See the graphical depiction.