Sarai has decided to take a risk. she's been saving money and now she's ready to invest in stocks. most of her stocks give her a great return, but one–bambi's beach bonnets–is a mixed story. the value of her shares in bambi's beach bonnets over timem is modeled by the function v(t) = −2x 2 + 22x + 280, where v represents the value of her investment and t represents time in weeks. (a) what key feature of the function tells us when her investment was worth the most?

vertex of the parabola

Step-by-step explanation:

v(t) = −2x²+ 22x + 280

v = value of her investment

t = time in weeks.

(a) What key feature of the function tells us when her investment was worth the most?

worth the most = highest value, so at the vertex of the parabola.

xvertex = -b/2a

yvertex = -Δ/4a

the revenue of the fitness center, y, is the product of two factors: the number of members and the fee paid by each member. there are 320 members now, but number of members goes down by 10 for each $5 increase in fees, so if x is the number of $5 price increases then members is equal to (320 - 10x). since the fee is currently $45, and the fee increases by $5 for every price bump x, the fee is given by (45 + 5x). so, revenue y is given by y = (320 - 10x)(45 + 5x).