Fall 2009 Math 151 2 1. Week in Review II ourtesy: David J. Manuel 2. (overing 1.2, 1.3 and 2.2) 1 1. 2. Setion 1.2 Find a · b if a = < 1, −1 > and b = i + 2j. 3. Find a · b for the gure below, given u is a unit vetor 4. b 5. a 6. u 3. 4. 5. Find the angle between the vetors < 3, 1 > and −2i + 4j. Setion 1.3 Find the Cartesian equation√ of the urve parametrized by x = t, y = 2t + 4 and sketh the graph. Given r(t) = (t1/2 + 1)i + t3/2 j: a) Find r(1) and r(t + h) b) When (if at all) does the graph pass through the point (3, 8)? ) Eliminate the parameter and sketh the graph. Desribe the motion of a partile whose position is given by x = −4 cos t, y = 3 sin t. Find vetor and parametri equations of the line passing through the points (−4, 2) and (2, 14). Determine whether the lines r1(t) = (3 − 4t)i + (4 + 3t)j and r2 (t) = (2 − 5t)i + (5 − 3t)j are parallel, perpendiular, or neither. If not parallel, nd their point of intersetion. A water balloon is thrown with initial veloity of 15 meters per seond at an angle of elevation of 30◦ . Soon you will be able to derive the following parametri equations for√the mo- Find x suh that the vetors xi + j and (4 + x)i + 3j are orthogonal. tion of the balloon: x = Given a =< 4, 5 > and b =< 1, −2 > nd the salar and vetor projetions of: a) b onto a b) a onto b the balloon will strike the ground and nd the Cartesian equation for the balloon's motion. 15 t − 4.9t2 . Determine how far away 2 7. 6. A 10-kg blok slides down a ramp whih is 5m tall and 8m long. Find the work done by gravity if the blok slides (frition-free) all the way down the ramp. 7. Find the distane from the point line (1, 5) 15 3 t, y = 2 to the 2x − 3y = 12. 1 How, if at all, does the graph of the funtion r(t) = ti + (t − 1)3 j dier from the graph of #2? 3 1. Setion 2.2 Use axomputational devie to estimate 2 −1 lim . x→0 2. 3. 4. x x2 + 1 Determine lim or show the limit x→1 x − 1 Does Not Exist. x2 + 1 Determine lim or show the x→3 (x − 3)2 limit Does Not Exist. Find the vertial asymptotes of f (x) = x2 − 4 . (x − 1)(x − 2)(x − 3)(x − 4) 2