Answer:

Step-by-step explanation:
cosine x²= cos x²
Rule
Given that,

![=\int ^1_0[\int^3_0(\int^9_{3y} \frac{6cos x^2}{5\sqrt z}dz)dy]dz](https://tex.z-dn.net/?f=%3D%5Cint%20%5E1_0%5B%5Cint%5E3_0%28%5Cint%5E9_%7B3y%7D%20%5Cfrac%7B6cos%20x%5E2%7D%7B5%5Csqrt%20z%7Ddz%29dy%5Ddz)
![=\int^1_0[\int^3_0([\frac{6cos x^2 \times \sqrt z}{5\times \frac{1}{2}}]^9_{3y})dy]dx](https://tex.z-dn.net/?f=%3D%5Cint%5E1_0%5B%5Cint%5E3_0%28%5B%5Cfrac%7B6cos%20x%5E2%20%5Ctimes%20%5Csqrt%20z%7D%7B5%5Ctimes%20%5Cfrac%7B1%7D%7B2%7D%7D%5D%5E9_%7B3y%7D%29dy%5Ddx)
![=\int^1_0[\int^3_0([\frac{12cos x^2 \times( \sqrt 9-\sqrt{3y})}{5}])dy]dx](https://tex.z-dn.net/?f=%3D%5Cint%5E1_0%5B%5Cint%5E3_0%28%5B%5Cfrac%7B12cos%20x%5E2%20%5Ctimes%28%20%5Csqrt%209-%5Csqrt%7B3y%7D%29%7D%7B5%7D%5D%29dy%5Ddx)
![=\int^1_0[\int^3_0([\frac{12cos x^2 \times( 3-\sqrt{3y})}{5}])dy]dx](https://tex.z-dn.net/?f=%3D%5Cint%5E1_0%5B%5Cint%5E3_0%28%5B%5Cfrac%7B12cos%20x%5E2%20%5Ctimes%28%203-%5Csqrt%7B3y%7D%29%7D%7B5%7D%5D%29dy%5Ddx)
![=\int^1_0[\frac{12cos x^2 \times( 3y-\frac{\sqrt{3}y^\frac{3}{2}}{\frac{3}{2}})}{5}]^3_0dx](https://tex.z-dn.net/?f=%3D%5Cint%5E1_0%5B%5Cfrac%7B12cos%20x%5E2%20%5Ctimes%28%203y-%5Cfrac%7B%5Csqrt%7B3%7Dy%5E%5Cfrac%7B3%7D%7B2%7D%7D%7B%5Cfrac%7B3%7D%7B2%7D%7D%29%7D%7B5%7D%5D%5E3_0dx)
![=\int^1_0[\frac{12cos x^2 \times( 3.3-\frac{2\sqrt{3}.3^\frac{3}{2}}{3})}{5}]^3_0dx](https://tex.z-dn.net/?f=%3D%5Cint%5E1_0%5B%5Cfrac%7B12cos%20x%5E2%20%5Ctimes%28%203.3-%5Cfrac%7B2%5Csqrt%7B3%7D.3%5E%5Cfrac%7B3%7D%7B2%7D%7D%7B3%7D%29%7D%7B5%7D%5D%5E3_0dx)
![=\int^1_0[\frac{12cos x^2 \times( 9-6)}{5}]dx](https://tex.z-dn.net/?f=%3D%5Cint%5E1_0%5B%5Cfrac%7B12cos%20x%5E2%20%5Ctimes%28%209-6%29%7D%7B5%7D%5Ddx)


![=\frac{18}{5}[(x+\frac{sin2x}{2})]^1_0](https://tex.z-dn.net/?f=%3D%5Cfrac%7B18%7D%7B5%7D%5B%28x%2B%5Cfrac%7Bsin2x%7D%7B2%7D%29%5D%5E1_0)

Answer:
Step-by-step explanation:
1) we have to find the area of the cut out portion
Since both circles in one side makes up the side 28cm
The diameter of each circle is 14cm
radius = diameter / 2
r = 7cm
Area of a circle = πr²
A = 22/7 × 7²
= 22/7 × 7 × 7
= 22 × 7 = 154cm²
So the four circles will make
= 154 + 154 + 154 + 154
= 616 cm²
The Area of the square will be
= L × L
= 28 × 28
= 784 cm²
Therefore the area of the remaining portion will be
Area of the square - total area of the circles
= 784 cm² - 616 cm²
= 168 cm²
The area of the remaining part is 168 cm²
Hello,
r=5(1+cos t)
r'=5(-sin t)
r²+r'²= 25[(1+cos t)²+(-sin t)²]=50(1-cos t)=50 sin² (t/2)
Between 0 and π, sin x>0 ==>|sin x|=sin x
![l= 2*5* \int\limits^{\pi}_0{sin( \frac{t}{2} )} \, dt= 5[-cos (t/2)]_0^{\pi}\\\\ =5(0+1)=5](https://tex.z-dn.net/?f=l%3D%202%2A5%2A%20%5Cint%5Climits%5E%7B%5Cpi%7D_0%7Bsin%28%20%5Cfrac%7Bt%7D%7B2%7D%20%29%7D%20%5C%2C%20dt%3D%205%5B-cos%20%28t%2F2%29%5D_0%5E%7B%5Cpi%7D%5C%5C%5C%5C%0A%3D5%280%2B1%29%3D5)
Here is the method but i may have make some mistakes.
Hey there,
It take 45 min to complete 75% of the wall
1% = 45 / 75
= 0.6
100 % = 0.6 x 100
= 60 min
It takes her 60 mins or 1 hour to finish building the wall.
Hope this helps :))
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