( 2 , 6 ) , ( 3 , 12 ) , ( 4 , 15 ) , ( 5 , 21 ) We want to find the line t = m s + q , with slope m and y-intercept q , that best fits this data. Namely, we go ahead and try to solve the system A x = b with A = ⎡ ⎢ ⎢ ⎢ ⎢ ⎣ 2 1 3 1 4 1 5 1 ⎤ ⎥ ⎥ ⎥ ⎥ ⎦ , b = ⎡ ⎢ ⎢ ⎢ ⎢ ⎣ 6 12 15 21 ⎤ ⎥ ⎥ ⎥ ⎥ ⎦ and x = [ m q ] However, this system is very likely to be inconsistent. So instead we write down the normal equation A T A x = A T b and solve it to get the least squares solution x = [ m , q ] T .

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

Number 5 is 50 degreesnumber 6 is 45 degreesnumber 7 is 60 degreesnumber 8 is 45 degrees