Ellipse is an elongated form of circle or in other words, circle is an special case of ellipse where the two radii of the circle are equal. Cvc An ellipse explained as a set of points such that the sum of distances from two fixed points (foci) is same for all points given a point P = (x, y), distances are d1 & d2, equation is :
d1 + d2 = constant _ _ _ (1)
In terms of local coordinates
F1 = (x1, y1) & F2 (x2, y2)
Equation is :
_ _ _ (2)
This can also be written in the form :
Ax2 + By2 + Cxy + Dx + Ey + F = 0 _ _ _ (3)
(More A, B, C, D, E, & F are evaluated in terms of focal coordinates & major minor axis).
• Major axis – which extends form 1 point to other through foci.
• Minor axis – which spans the shouter dimension bisecting major axis at ellipse center.
An interactive method for specifying an ellipse in an arbitrary orientation is to input two foci & a point on ellipse boundary & evaluate constant in equation (1) & so on.
Equation can be simplified if ellipse is in “standard position” with major & minor axis oriented parallel to x and y axis.
y

yc

xc x
= 1 _ _ _(4)
Now using polar coordinates r & θ
Parameter equations are :
x = xc + rx cos θ
y = yc + ry sin θ

TalkTalk, a British phone and broadband provider with more than four million customers, disclosed Friday that intruders had hacked its Web site and may have stolen personal and financial data. Sources close to the investigation say the company has received a ransom demand of approximately £80,000 (~USD $122,000), with the attackers threatening to publish the TalkTalk’s customer data unless they are paid the amount in Bitcoin.
In a statement on its Web site, TalkTalk said a criminal investigation was launched by the Metropolitan Police Cyber Crime Unit following “a significant and sustained cyberattack on our website.”
“That investigation is ongoing, but unfortunately there is a chance that some of the following data has been compromised: names, addresses, date of birth, phone numbers, email addresses, TalkTalk account information, credit card details and/or bank details,” the statement continues. “We are continuing to work with leading cyber crime specialists and the Metropolitan Police to establish exactly what happened and the extent of any information accessed.”
A source close to the investigation who spoke on condition of anonymity told KrebsOnSecurity that the hacker group who demanded the £80,000 ransom provided TalkTalk with copies of the tables from its user database as evidence of the breach. The database in question, the source said, appears related to at least 400,000 people who have recently undergone credit checks for new service with the company. However, TalkTalk’s statement says it’s too early to say exactly how many customers were impacted. “Identifying the extent of information accessed is part of the investigation that’s underway,” the company said.
Separately, promises to post the stolen data have appeared on AlphaBay, a Deep Web black market that specialized in selling stolen goods and illicit drugs. The posting was made by someone using the nickname “Courvoisier.” This member, whose signature describes him as “Level 6 Fraud and Drugs seller,” appears to be an active participant in the AlphaBay market with many vouches from happy customers who’ve turned to him for illegal drugs and stolen credit cards, among other goods and services.