See attached for a sketch of some of the cross sections.
Each cross section has area equal to the square of the side length, which in turn is the vertical distance between the curve y = √(x + 1) and the x-axis (i.e. the distance between them that is parallel to the y-axis). This distance will be √(x + 1).
If the thickness of each cross section is ∆x, then the volume of each cross section is
∆V = (√(x + 1))² ∆x = (x + 1) ∆x
As we let ∆x approach 0 and take infinitely many such cross sections, the total volume of the solid is given by the definite integral,

Step-by-step explanation:
slope interception formula is
y-y1=m(x-x1)
where m is m=y-y1/x-x1 in this case m=-2 because the line we are trying to find is parallel to the given one y=-2x-6 where slope k=-2
so the final equation would be
y-1=-2(x-(-4))
y-1=-2x-2*4
y=-2x-8+1=-2x-7
Sin(theta)=√3/2, 0≤theta≤360
In a unit circle, sin is y/r, r is always positive, y is positive in the first and second quadrant only.
sin60=√3/2, sin120=√3/2
so theta is 60 or 120