So the 3x means three times then u multiply by three
6n + 8n
Which is 6 * n + 6 * 8, n being a number.
C=2pir
20pi=2pir
20pi/2pi=2pir/2pi
R=10
Height=10/2=5
Two circles surface areas is
2*pir^2
2pi10^2
2*100pi
200pi
The cylindrical part is
2pirh
2pi*10*5
100pi
Add 100pi+200pi=300pi
That is a description of the formula for the rectangle rule using left endpoints.
The formula for the discriminant is b^2-4ac. The formula you wote is in the form of
ax^2+c=0, so first, you need to bring that -2 to the left. When you do that, you get (the original equation would be ax^2+bx+c but you have no bx.)
3x^2-8
So, since there's no b, it would be
b^2-4ac
0^2-4(3)(-8
-12 x -8
96
