(a-b) X (a+b)
= aXa - bXa +aXb -bXb (distributing)
Now, cross product of a vector with itself = 0
so, aXa = 0, bXb = 0
Also, aXb = - bXa
so,
(a-b) X (a+b) = 0 + aXb + aXb + 0
= 2aXb
hence, proved :)
Answer:
your answer will be <u>0</u>
Step-by-step explanation:

axis of symmetry
when b=0

hope it helps :)
have a nice weekend!!!
Answer:
2.67 inches.
Step-by-step explanation:
Assuming that we represent the size of the squares with the letter y, such that after the squares are being cut from each corner, the rectangular length of the box that is formed can now be ( 23 - 2y), the width to be (13 - 2y) and the height be (x).
The formula for a rectangular box = L × B × W
= (23 -2y)(13-2y) (y)
= (299 - 46y - 26y + 4y²)y
= 299y - 72y² + 4y³
Now for the maximum volume:
dV/dy = 0
This implies that:
299y - 72y² + 4y³ = 299 - 144y + 12y² = 0
By using the quadratic formula; we have :

where;
a = 12; b = -144 and c = 299






Since the width is 13 inches., it can't be possible for the size of the square to be cut to be 9.33
Thus, the size of the square to be cut out from each corner to obtain the maximum volume is 2.67 inches.
Answer: The total cost in dollars of the gas is $77.80.
Step-by-step explanation:
since we have given that
Amount of gallon of gas he bought for the first time = 12.53
Amount of gallon of gas he bought for the second time = 11.86
According to question, He paid $3.19 per gallon both the times that he stopped for gas on a weekend trip.
So, our expression that shows the total cost in dollars of the gas he bought on this trip is given by

Hence, the total cost in dollars of the gas is $77.80.
Answer:
A, D and C.
Step-by-step explanation: