Evaluate the function when x=-3,0 and 2. f(x)=15x+4

2people are trying different phones to see which one has the better talk time. chatlong has an average of 18 hours with a standard deviation of 2 hours and talk-a-lot has an average of 20 hours with a standard deviation of 3. the two people who tested their phones both got 20 hours of use on their phones. for the z-scores i got 1 for the chatlong company and 0 for talk-a-lot. what is the percentile for each z-score?

With finding limits of multi variable !

Find the condition that the zeros of the polynomial f(x) = x^3+3px^2+3px+r may be in a.p.