Answer:
0
Step-by-step explanation:
∫∫8xydA
converting to polar coordinates, x = rcosθ and y = rsinθ and dA = rdrdθ.
So,
∫∫8xydA = ∫∫8(rcosθ)(rsinθ)rdrdθ = ∫∫8r²(cosθsinθ)rdrdθ = ∫∫8r³(cosθsinθ)drdθ
So we integrate r from 0 to 9 and θ from 0 to 2π.
∫∫8r³(cosθsinθ)drdθ = 8∫[∫r³dr](cosθsinθ)dθ
= 8∫[r⁴/4]₀⁹(cosθsinθ)dθ
= 8∫[9⁴/4 - 0⁴/4](cosθsinθ)dθ
= 8[6561/4]∫(cosθsinθ)dθ
= 13122∫(cosθsinθ)dθ
Since sin2θ = 2sinθcosθ, sinθcosθ = (sin2θ)/2
Substituting this we have
13122∫(cosθsinθ)dθ = 13122∫(1/2)(sin2θ)dθ
= 13122/2[-cos2θ]/2 from 0 to 2π
13122/2[-cos2θ]/2 = 13122/4[-cos2(2π) - cos2(0)]
= -13122/4[cos4π - cos(0)]
= -13122/4[1 - 1]
= -13122/4 × 0
= 0
Answer:
<em>(a) x=2, y=-1</em>
<em>(b) x=2, y=2</em>
<em>(c)</em> 
<em>(d) x=-2, y=-7</em>
Step-by-step explanation:
<u>Cramer's Rule</u>
It's a predetermined sequence of steps to solve a system of equations. It's a preferred technique to be implemented in automatic digital solutions because it's easy to structure and generalize.
It uses the concept of determinants, as explained below. Suppose we have a 2x2 system of equations like:

We call the determinant of the system

We also define:

And

The solution for x and y is


(a) The system to solve is

Calculating:





The solution is x=2, y=-1
(b) The system to solve is

Calculating:





The solution is x=2, y=2
(c) The system to solve is

Calculating:





The solution is

(d) The system to solve is

Calculating:





The solution is x=-2, y=-7
10 to 11 = 1 hr
11 to 12 = 1 hr
12 to 1 = 1 hr
total = 3 hours
Answer:
for first blank its 1/3 and second blank is 5
Step-by-step explanation:
Answer:
its A.
Step-by-step explanation: