Answer:
Step-by-step explanation:
Parameterize the ellipse as (acos∙,bsin∙). Take points P:=(acosp,bsinp) and Q:=(acosq,bsinq) on the ellipse, with midpoint M:=(P+Q)/2.
If |PQ|=2k, then
a2(cosp−cosq)2+b2(sinp−sinq)2=4k2
The coordinates of M are
xy==a2(cosp+cosq)b2(sinp+sinq)
Answer:
Step-by-step explanation:
You can split the coins into 3 groups, each of them has 3 coins. Weigh group 1 vs group 2, if one is lighter, that group has the fake coin. If both groups weigh the same, then group 3 has the fake coin.
Continue to split the group that has the fake coin into 3 groups, each group has 1 coin. Now apply the same procedure and we can identify the fake coin.
Total of scale usage is 2
b) if you have 
coins then you can apply the same approach and find the fake coin with just n steps. By splitting up to 3 groups each step, after each step you should be able to narrow down your suspected coin by 3 times.
Step 1: you narrow down to group of 
coins
Step 2: you narrow down to group of 
coins
Step 3: you narrow down to group of 
coins
...
Step n: Step 1: you narrow down to group of 
coin
5 because 20:6 is the car to motorcycle.
6:15 is the motorcycle to van.
20÷15=5
~JZ
Answer:
it can be written as 6/1 divided by 1/2
then you'll use the keep, switch, flip method. keep 6/1, switch division to multiplication, and flip 1/2 to become 2/1 or 2
now your equation is 6 x 2 = 12
Julio did 6 divided by 2. which could've been fixed if he changed the division sign to multiplication and multiplied
