Answer:
a) -1
Step-by-step explanation:
Slope is also known as the gradient
1. assign a value to x and solve for y:
when x = 2, y = 2
when x = 4, y = 0
2. Next, use the equation of a straight line to find the gradient
y = mx + c
y is the y-coordinate, m is the gradient, x is the x-coordinate, c is the point where the line crosses the y-axis, which is found by equating y to 0 and solving for x
so y = mx + c becomes 2 = m*2 + 4, which then becomes 2 = 2m + 4
2m = -2 (take 4 away from 2)
<u>m = -1 </u>
and inner radius 
![\displaystyle V = \int_0^1 \pi\Big[ \left( 2 - x^2 \right)^2 - \left( 2 - \sqrt{x}\right)^2\Big] dx](https://tex.z-dn.net/?f=%5Cdisplaystyle%20V%20%3D%20%5Cint_0%5E1%20%5Cpi%5CBig%5B%20%5Cleft%28%202%20-%20x%5E2%20%5Cright%29%5E2%20-%20%5Cleft%28%202%20-%20%5Csqrt%7Bx%7D%5Cright%29%5E2%5CBig%5D%20dx)
