Cracking The Ap Calculus ab Exam 2018

(Marvins-Underground-K-12) #1
Note    that    the curve   is  above   the x-axis  from    x   =   1   to  x   =       and below   the x-axis  from    x   =       to

x   =   2.  Thus,   we  need    to  evaluate    two integrals   to  find    the area.

    cos x   dx  +    (− cos x)  dx

We  will    need    a   calculator  to  evaluate    these   integrals.

    cos x   dx  +    (−cos  x)dx    ≈   0.249

44. D First, we find ∫cot x dx by rewriting the integral as .


Then,   we  use u-substitution. Let u   =   sin x   and du  =   cos x.

Substituting,   we  can get     =   ln|u|   +   C.  Then    substituting    back,   we  get ln(sin

x)  +   C.  (We can get rid of  the absolute    value   bars    because sine    is  always  positive    on  the
interval.)

Next,   we  use f   =   1   to  solve   for C.  We  get 1   =   ln  +   C.
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