Cracking The Ap Calculus ab Exam 2018

(Marvins-Underground-K-12) #1

  1. C There are two ways we could evaluate this limit. First, we could recognize that this limit is in


the  form    of  the     Definition  of  the     Derivative  .   Then    the     limit   is  the

derivative  of  f(x)    =   tan x   at  x   =    .  The derivative  of  f(x)    =   tan x   is  f′(x)   =   sec^2 x,    and at  x   =    ,

we  get f′  =   sec^2   =   2.  Second, we  have    a   limit   of  the indeterminate   form     ,  so  we  can

use  L’Hôpital’s     Rule    to  find    the     limit.  Take    the     derivative  of  the     numerator   and     the

denominator:        =    .  Now we  take    the limit   to  get sec^2

= 2.


  1. A First, rewrite the integral as .


Now,    we  can simplify    the integral    to  .

Next, use the power rule for integrals, which is ∫ xn dx = + C.


Then,   we  get     =   .


  1. A The simplest thing to do here is to find of both pieces of the function and set them equal to


each    other.  We  can do  this    by  plugging    x   =   1   into    both    pieces: 1   −   3k  +   2   =   5   −   k.  If  we  solve

for k,  we  get k   =   −1.


  1. C The curve y = 8 + 2x − x^2 is an upside-down parabola and looks like the following:

Free download pdf