X=2 shown in the work below.
Answer:
V = 128π/3 vu
Step-by-step explanation:
we have that: f(x)₁ = √(4 - x²); f(x)₂ = -√(4 - x²)
knowing that the volume of a solid is V=πR²h, where R² (f(x)₁-f(x)₂) and h=dx, then
dV=π(√(4 - x²)+√(4 - x²))²dx; =π(2√(4 - x²))²dx ⇒
dV= 4π(4-x²)dx , Integrating in both sides
∫dv=4π∫(4-x²)dx , we take ∫(4-x²)dx and we solve
4∫dx-∫x²dx = 4x-(x³/3) evaluated -2≤x≤2 or too 2 (0≤x≤2) , also
∫dv=8π∫(4-x²)dx evaluated 0≤x≤2
V=8π(4x-(x³/3)) = 8π(4.2-(2³/3)) = 8π(8-(8/3)) =(8π/3)(24-8) ⇒
V = 128π/3 vu
Answer:
2nd one
Step-by-step explanation:
If you divide decimals you have to bring up the decimal point but if you divide whole numbers you dont have any decimal points so you just divide the numbers. Sorry if i didnt help i just wanted to help.
Answer:
positive
Step-by-step explanation:
The discriminant is positive
If there are 2 real roots ( where it crosses the x axis), then the discriminant is positive