Find area under the curve? Pl refer to the question in the img attached

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1 Answer
Dec 24, 2017

#A=49#

Explanation:

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This is a piece-wise function. We have to find the area under each piece separately and add them up.

#y=-1#

The area under this piece from #-2# to #0# is:

#A_1=int_-2^0 -dx=-x=-(0)-(-(-2))=0-2=-2#

#y=(x+2)^2#

The area under this piece from #0# to #3# is:

#A_2=int_0^3(x+2)^2dx#

Let #u=x+2#, then #du=dx#

#A_2=intu^2du=1/3u^3=1/3(x+2)^3=1/3(3+2)^3-1/3(0+2)^3#

#A_2=125/3-8/3=117/3=39#

#y=x#

The area under the curve for this piece from #3# to #5# is:

#A_3=int_3^5xdx=1/2x^2=1/2(5)^2-1/2(3)^2=25/2-9/2=16/2=8#

Area under the piece-wise function is:

#A=A_1+A_2+A_3=2+39+8=49#