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,

Answer:
The value of cos Ф is ± 
Step-by-step explanation:
There are important rules for sin Ф and cos Ф
∵ sin Ф = 
∴ sin²Ф = 
∴ sin²Ф = 
→ By using the third rule above
∵ cos²Ф = 1 - sin²Ф
∴ cos²Ф = 1 - 
∴ cos²Ф = 
→ Take square root for both sides
∴ cos Ф = ± 
∴ The value of cos Ф is ± 
-3x + 4y = 12
x - y = 1....x = y + 1
-3(y + 1) + 4y = 12
-3y - 3 + 4y = 12
-3y + 4y = 12 + 3
y = 15
x - y = 1
x - 15 = 1
x = 1 + 15
x = 16
one solution (16,15)
Irrational number
There is a chart on goggle
Answer:
3/4
Step-by-step explanation:
Since we have two points, we can use the slope formula
m = ( y2-y1)/(x2-x1)
= ( 5 - -1)/( 4 - -4)
= ( 5+1)/(4+4)
= 6/8
= 3/4