
William W. answered 02/22/20
Experienced Tutor and Retired Engineer
The slope of the tangent line of y = x2 is the derivative function. The derivative of y = x2 is y' = 2x.
The slope of the tangent line of y = √x is the derivative function. The derivative of y =√x is y' = 1(2√x).
If the lines are parallel, then their slopes are equal so 2x must equal 1(2√x).
2x = 1(2√x)
2x(2√x).= 1
4x3/2 = 1
x3/2 = 1/4
x = (1/4)2/3
x = 1/cuberoot(16) = 1/(2cuberoot(2)) = cuberoot(4)/4 ≈ 0.39685