Question 1021214
a) g increases from [-3,3]. From the graph the function f cross the x axis and the total area starts decreasing.
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*[illustration dx5.JPG].
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b) Break up the integral into 3 regions.
[-3,0]
{{{g[1](x)=int((3),dx,-3,x)}}}
{{{g[1](x)=3x+9}}}
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[0,6]
{{{g[2](x)=g[1](0)+int((-x+3),dx,0,x)}}}
{{{g[2](x)=9-x^2/3+3x}}}
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[6,9]
{{{g[3](x)=g[2](6)+int((-3),dx,6,x)}}}
{{{g[3](x)=9-3(x-6)}}}
{{{g[3](x)=27-3x}}}