18. FINANCIAL LITERACY The average annual price of crude oil can be modeled by the cubic function f(x) = 0.2728x^3- 2.612x^2+ 7.02x + 89.18, where x is the number of years after Gena began driving and f(x) is the price in dollars.
a. Graph the function for 0≤ x ≤ 10
b. Describe the turning points of the graph and its end behavior.
c. What trends in crude oil prices does the graph suggest?
d. Is it reasījnable that the trend will continue indefinitely? Explain.

Intersecting secant-tangent theorem states that if a tangent segment and a secant segment are drawn to a circle from an exterior point, then the square of the measure of the tangent segment is equal to the product of the measures of the secant segment and its external secant segment.so to break it down: 1. pq acts as the tangent and ps as the secant with an intersection at p.sr = 21rp = 3x + 3pq = 4x + 4following to equation: tangent squared = the two segments multiplied by each otherso (4x + 4) ^ 2 = (3x + 3) • (21) simplifies to 16x^2 - 31x - 47 = 0 or (16x - 47)(x + 1) x = -1 or x = 47/162. pq acts as the tangent and ps as the secant with an intersection at p (again! )sr = 16rp = xpq = 15(15) ^ 2 = 16 • x225 = 16xx = 225/163. the interesting chords are proportional to each other so a ratio is possible to set up: ap dp 10 3 + x = = —— = pc pb 8 xcross multiple to get 10x = (3 + x)(8)x = 12