Answer:
A
Step-by-step explanation:
I honestly couldn't tell you how to do this, I don't understand it. I just took the test and got this question correct. The answer is A, (5-7)^2.
The question is incomplete. Here is the complete question.
Find the measurements (the lenght L and the width W) of an inscribed rectangle under the line y = -x + 3 with the 1st quadrant of the x & y coordinate system such that the area is maximum. Also, find that maximum area. To get full credit, you must draw the picture of the problem and label the length and the width in terms of x and y.
Answer: L = 1; W = 9/4; A = 2.25;
Step-by-step explanation: The rectangle is under a straight line. Area of a rectangle is given by A = L*W. To determine the maximum area:
A = x.y
A = x(-)
A = -
To maximize, we have to differentiate the equation:
= (-)
= -3x + 3
The critical point is:
= 0
-3x + 3 = 0
x = 1
Substituing:
y = -x + 3
y = -.1 + 3
y = 9/4
So, the measurements are x = L = 1 and y = W = 9/4
The maximum area is:
A = 1 . 9/4
A = 9/4
A = 2.25
Answer:
52.5 kg ANS
Step-by-step explanation:
Weight of a pile of sand = 90kg
Ratio of weight of sand in three bags = 2:3:7
Let the weight be 2x kg, 3x kg, 7x kg respectively A.T.Q.
= 2x + 3x +7x = 90
= 12x = 90
= X= 90/12
= X = 7.5 kg
Weight of sand in medium bag =
= 3 × 7.5
= 52.5 kg ANS
I hope this answer is correct
A B
D C
vectors
AB = DC
AB (-2-7 ; 3-1) => AB (-9 ; 2)
DC (1-x : -7-y)
1 - x = -9 => x = 10
-7-y = 2 => y = -9
D(10 ; -9)