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 is B. Hope this helps
Could I please get brainliest answer?
Answer:
D
Step-by-step explanation:
Imagine this as a right angle triangle, where the diagonal length is the hypotenuse, the length is one side, and the width is the other.
We can therefore use Pythagoras' Theorem (or Pythagorean Theorem) to solve. The formula for this is a²+b²=c², where c is the hypotenuse, and a and b are the sides.
We can input the values we know to this formula to get the width. This gives 110²+b²=133.14² or 12100+b²=17 726.2596.
From there subtracting 12100 from both sides gives b²=5626.2596.
Square rooting b isolates it, leaving b=75.0083969.
Since the value of the diagonal was approximate, this can be assumed the b is 75m.
**This content involves Pythagoras' Theorem/Pythagorean Theorem, which you may wish to revise. I'm always happy to help!
Answer:
volume = 1134.6 cm³
Step-by-step explanation:
volume = 8.2 x 13.7 x 10.1 = 1134.6 cm³
Answer:
177
Step-by-step explanation:
Although it says that 82 studied in both, the question is aksing for ONLY at the library. It says that of the 270 surveyed, 177 study at the library.
This means that 65.56% of the students studied at the library primarely.