Answer:
Area of the new rectangle = 148.8 cm square
Step-by-step explanation:
Let x be the dimensions of the rectangle then the
Perimeter of the Original rectangle= 2(L+B)
= 2 ( 3x+2x) = 2(5x)= 10xcm
If the length is increased by eight the new length would be 3x+ 8
and width would be 2x+x= 3x after 50 % increase
Perimeter of the new rectangle= 2(L+B)
= 2 ( 3x+8 +3x)
= 2 (6x+8)
= 12x + 16
Ratio of the new perimeter to the original perimeter is
New perimeter : Original perimeter
8 : 5
12x+ 16 : 10x cm
80x= 60x + 16
20x= 16
x= 16/20= 4/5
Putting the value of length and breadth in place of x
Area of the new rectangle = L*B = 3 * (4/5) +8 *3(4/5)=
= 12+ 40/5 * 12/5
= 62/5* 12/5
= 744/5
= 148.8 cm square
An absolute value is positive value of any value. So the abs value of -28 is 28. The abs value of 67 is 67. Makes sense?
If it were |27-3| for example, treat the inside of a abs as parenthesis, so you must complete PEMDAS inside of it to reduce the equation to |24|, unless you wanted it to become |27| - |3|.
For functions, this becomes slightly different and more difficult, especially when adding a variable such as x. Look below for a sample equation.
|2x-3|=1
This equation will actually have (and most others) 2 solutions for x. To find these, you’ll need to multiply the inside of the abs by -1 for one equation, and leave it as it is for the other!
2x-3=1 -(2x-3)=1
Now you have to solve BOTH equations to get your correct x-value answers.
For the first listed equation:
2x=4
x=2
For the second listed equation:
-2x+3=1
-2x=-2
x=-1
So you get the x-values -1 and 2 which both make the parent function true!
Answer:
centre (3 ,-1) , r=9
Explanation:
The standard form of the equation of a circle is.
∣
∣
∣
∣
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
a
a
(
x
−
a
)
2
+
(
y
−
b
)
2
=
r
2
a
a
∣
∣
−−−−−−−−−−−−−−−−−−−−−−−−−
where (a,b) are the coordinates of the center and r , the radius.
For the given equation: a = 3 , b = -1 and r = 9
hence centre = (3 ,-1) and radius = 9
Step-by-step explanation:
Answer:
The volume of the solid is 
Step-by-step explanation:
In this case, the washer method seems to be easier and thus, it is the one I will use.
Since the rotation is around the y-axis we need to change de dependency of our variables to have
. Thus, our functions with
as independent variable are:
For the washer method, we need to find the area function, which is given by:
![A=\pi\cdot [(\rm{outer\ radius)^2 -(\rm{inner\ radius)^2 ]](https://tex.z-dn.net/?f=A%3D%5Cpi%5Ccdot%20%5B%28%5Crm%7Bouter%5C%20radius%29%5E2%20-%28%5Crm%7Binner%5C%20radius%29%5E2%20%5D)
By taking a look at the plot I attached, one can easily see that for a rotation around the y-axis the outer radius is given by the function
and the inner one by
. Thus, the area function is:
![A(y)=\pi\cdot [(\sqrt{y} )^2-(y^2)^2]\\A(y)=\pi\cdot (y-y^4)](https://tex.z-dn.net/?f=A%28y%29%3D%5Cpi%5Ccdot%20%5B%28%5Csqrt%7By%7D%20%29%5E2-%28y%5E2%29%5E2%5D%5C%5CA%28y%29%3D%5Cpi%5Ccdot%20%28y-y%5E4%29)
Now we just need to integrate. The integration limits are easy to find by just solving the equation
, which has two solutions
and
. These are then, our integration limits.
