Pi4 is a short toxin found at very low abundance in the venom of Pandinus imperator scorpions. It is a potent blocker of K+ channels. Like the other members of the -KTX6 subfamily to which it belongs, it is cross-linked by four disulfide bonds. The synthetic analog (sPi4) and the natural toxin (nPi4) have been obtained by solid-phase synthesis or from scorpion venom.
A=pir2 a=pi2r2 a=pi4 r2 a increases by 4 times
By calculating the areas of circles with diameters 6 and 4 and comparing those: pi3^2=pi9 pi2^2=pi4 pi9/pi4=9/4=2.25 So the 6 inch pipe holds 2.25 times as much as the 4 inch pipe.
"It's Fundamental Operations and not fundamental numbers.The four fundamental operations in Mathematics are addition, Subtraction, Multiplication and Division."If i would have to name four fundamental numbers of mathematics I would say:1. number: 0 (zero)2. number: 1 (one)3. number: Pi4. number: Euler's number
ATA/ATAPI -4, ATA/ATAPI -5, ATA/ATAPI -6, ATA/ATAPI -7 (SATA)
If that is a product, (pi-x) times (sec squared x), then you can use the product rule for derivatives. For the power, sec squared x, which simply means (sec x) squared, you can use the chain rule.