The hourly temperature at Portland, Oregon, on a particular day is recorded below. 1 A. M. 2 3 4 5 6 7 8 9 10 11 12 Noon 46° 44° 43° 41° 40° 40° 41° 43° 46° 52° 65° 69° 1 P. M. 2 3 4 5 6 7 8 9 10 11 12 Midnight 72° 74° 75° 75° 77° 75° 74° 70° 62° 55° 51° 48° a. Find the amplitude of a sinusoidal function that models this temperature variation. b. Find the vertical shift of a sinusoidal function that models this temperature variation. c. What is the period of a sinusoidal function that models this temperature variation? d. Use t = 0 at 5 P. M. to write a sinusoidal function that models this temp. variation. e. What is the model’s temperature at 10 A. M.? Compare this to the actual value?

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