How do you find an equation of the tangent line to the curve y = arcsin(x/2) at the point where x = −sqrt2?

1 Answer
Apr 13, 2015

First find the derivative of arcsin(x/2). It would be 1/2 1/sqrt(1-x^2/4). This would give the slope of the tangent line at any given point of which x coordinate is known. In the present case it is x= -sqrt2.

The slope would accordingly be 1/2 1/sqrt(1-2/4) = 1/sqrt2.

For x= -sqrt2, y= arcsin(-sqrt2 /2) = -pi/4.

Equation of tangent line, in the point slope form, would be y+pi/4= 1/sqrt2 ( x +sqrt2)