In the case of a 2 Ã 2 matrix, the specific formula for the determinant is simply the upper left element times the lower right element, minus the product of the other two elements.
Before you buy any extended warranty... An extended warranty should not be a rush purchase! Before buying any extended warranty, read the contract carefully. Be sure you understand what is and what is not covered, where you can have your car repaired, and whether there are any deductibles or limits on your coverage.emember, you do not need to purchase your extended warranty from the dealership. If your dealer tells you that you cannot obtain financing without buying an extended warranty or that you can only buy an extended warranty when you purchase the car, it's time to find a new dealer.
Existing warranties. The first thing to consider before buying an extended warranty is the warranty that comes with the new product. Shoppers should check what's covered under a free warranty, which typically lasts for 12 months, before buying an extended warranty. How you pay for the product can matter.or Bryan Finnerty, co-founder and CEO of ProtectCELL, which sells extended warranties for phones and tablets, if the warranty price nears half the cost of the product's retail price, then shoppers should probably pass on it.