Cracking The Ap Calculus ab Exam 2018

(Marvins-Underground-K-12) #1
the Pythagorean Theorem,    we  also    know    that    when    y   =   30  and x   =   45, z   =   54.08.

Step    4:  Now we  plug    everything  into    the equation    from    Step    2   and solve   for .

(45)(18) + (30)(12) = (54.08)

1,170 = (54.08)

21.63 =


  1. B This question is testing your knowledge of the rules of definite integrals.


Step    1:  Generally   speaking,    f(x)dx +    f(x)dx =    f(x)dx.

So  here,    f(x)   dx  +    f(x)   dx  =    f(x)   dx.

If  we  substitute   f(x)   dx  =   A   and  f(x)   dx  =   B,  we  get  f(x)   dx  +   B   =   A.


  1. D This problem requires you to know how to find the derivative of an inverse function.


Step    1:  The rule    for finding the derivative  of  an  inverse function    is

If  y   =   f(x)    and if  g(x)    =   f −1(x),    then    g′(x)   =   

Step    2:  In  order   to  use the formula,    we  need    to  find    the derivative  of  f   and the value   of  x   that
corresponds to y = 10.

First,  f′(x)   =   6x  −   1.  Second, when    y   =   10  we  get 10  =   3x^2    −   x.

If  we  solve   this    for x,  we  get x   =   2   and x   =   − , but we’ll   use 2—it’s  easier.

Step    3:  Plugging    into    the formula,    we  get .

Note:   There   was another possible    answer  using   x   =   − , but that    doesn’t give    us  one of  the
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