Find points on curve with a tangent line

[dvaughn]

Homework Statement

Find points on curve y=sinhx where the tangent line has slope 2

Homework Equations

The Attempt at a Solution

y' = 1/(sqrt(1-x^2)) = 2
4 = 1/(1-x^2)
4-4x^2=1
x=sqrt(3/4)

the actual answer should be x = +or- ln(2+sqrt(3))

 

[rock.freak667]

d/dx(sinhx)=coshx = (e^x+e^-x)/2

then solve for e^x

 

[Bohrok]

Remember that the derivative of arcsin x or sin^-1x = 1/√(1 - x²). sinh is the hyperbolic sine.