# Calculus

posted by .

Find the equation of the line tangent to the graph of y=4 e^x at x=2.

I always get confused with tangent lines
I worked this out to be

4e^x(x-2)+4e^2 but the program i have to submit it to says its wrong.

• Calculus -

The equation of the tangent to the graph
y=f(x) at x=a:
y=f(a)+f'(a)(x-a)
(4e^x)'=4e^x
y=4e^2+4e^2(x-2)
y=4e^2*x-4e^2

## Similar Questions

1. ### cal

Equations of the tangent lines to hyperbola xy=1 that pass through point (-1,1) I know the graph of y=1/x but not sure about the tangent lines at given point. Are the lines tangent to (1,1) and (-1,-1)?
2. ### Calculus

55. Find an equation of the tangent line to the graph of f(x) =x^3 - 2x + 1 a) at (2,5); b) at (-1,2); c) at (0,1). I believe the answers are: a) y= (3/2 x) - (3/2) b) No solution c) No solution For each function, find the points on …
3. ### Calculus Tangent lines

find the equation of a tangent line of x^(1/4) + y^(1/4) = 4 at the point (16,16)
4. ### calculus

find the equation of a quadratic function whose graph is tangent at x=1 to the line whose slope8, tangent at x=-2 to solve the line with slope-4 and tangent to the line y=-8
5. ### cal

find the equation of a quadratic function whose graph is tangent at x=1 to the line whose slope8, tangent at x=-2 to solve the line with slope-4 and tangent to the line y=-8 find the equation of the tangent lines at x=1 and x=-2 graph …
6. ### College Calculus

Let f(x) = 3x^2 - 2x + 1 a) write an equation of the line going through the points (1, f(1)), and (2, f(2)). b) Find a point on the graph of f where the tangent line to the graph has the same slope as the line in part (a). Write the …
7. ### calculus

i'm not sure how to do this. can someone help, please?
8. ### Calculus

The function g is defined for x>0 with g(1)=2, g'(x)=sin(x+1/x), and g"(x)=(1-1/x^2)cos(x+1/x). A. Find all values of x in the interval 0.12<=x<=1 at which the graph of g has a horizontal tangent line. B. On what subintervals …
9. ### Calculus AB

Sorry but I've got a lot of problems that I don't understand. 1) Let f(x)= (3x-1)e^x. For which value of x is the slope of the tangent line to f positive?