Of course you can use the quotient rule, but it is usually not the easiest method. If we do use it here, we get $${d\over dx}{10\over x^2}={x^2\cdot 0-10\cdot 2x\over x^4}= {-20\over x^3},$$ since the derivative of 10 is 0.
1 Young children can't tell the difference between fantasy and reality. 2  Your preschooler's rich imagination is a big part of his normal development, but that means it is usually hard for him to tell the difference between what's real and what's imaginary.
Most developmentalists consider perception to be an automatic process that everyone experiences the same way. 1  Only infants aged 9 months or older notice the difference between a solid surface and an apparent cliff. 2  If a 5-month-old drops a rattle out of the crib, the baby will not look down to search for it.