# How do you find the equation of the tangent line and normal line to the curve at the given point #y = (1+2x)^2#, (1,9)?

##### 1 Answer

Sep 16, 2015

equation of tangent is

equation of normal line is

#### Explanation:

the slope of tangent at (1,9) is

at x=1 the slope value is 12

let the equation of tangent is y=mx+c

substituiting points

9=12+c

c=-3

equation of tangent is y=12x-3

for normal line

slope =-1/12

from the line formula y=mx+c

substituiting points

9=-1/12+c

c=109/12

equation is

12y = 109-x