Do you know the answer? Help me!
2 answers:
You might be interested in
Answer:
Length, l = 11 ft.
Width, w = 9 ft.
Step-by-step explanation:
From the given data, the area of the rectangle = 99 ft².
Area of the rectangle = Length, l X Width, w
Here, Length, l = 7 more than twice the width
⇒ Length, l = 7 + 2w
Therefore, Area, A = 99 = (7 + 2w)w
⇒ 99 = 7w + 2w²
⇒ 2w² + 7w - 99 = 0
Solve the Quadratic equation using the formula: x = for the quadratic equation ax² + bx + c = 0.
Therefore, w =
Since, we get:
This gives two values of 'w', viz., w = ,
⇒ w = , -9.
We take the integer values.
If w = -9, then l = 2(-9) + 7
⇒ l = - 18 + 7 = - 11
Therefore, the length, l of the rectangle = - 11 ft.
and the width, w of the rectangle = - 9 ft.
Hence, the answer.
Answer:
<em>The largest rectangle of perimeter 182 is a square of side 45.5</em>
Step-by-step explanation:
<u>Maximization Using Derivatives</u>
The procedure consists in finding an appropriate function that depends on only one variable. Then, the first derivative of the function will be found, equated to 0 and find the maximum or minimum values.
Suppose we have a rectangle of dimensions x and y. The area of that rectangle is:
And the perimeter is
We know the perimeter is 182, thus
Simplifying
Solving for y
The area is
Taking the derivative:
Equating to 0
Solving
Finding y
The largest rectangle of perimeter 182 is a square of side 45.5