I need help .-. Calc https://padlet-uploads.storage.googleapis.com/1140267424/aeb3c96a1f1771b861f8e4382ef5baef/Screenshot_2021_05_03_at_7_51_39_PM.png
@AZ
find the eq. of two lines on left of y-axis and right of y-axis.also find the eq. of circle with center (5,3) and radius=3 take f(x)=y break interval from -2 to 0,0 to 2 and 2 to 5 integrate inthese intervals ,then add you get integration -2 to 5 integration from -6 to 5=integration from -6 to -2 plus integration from -2 to 5 from this you can find your reqd.result for (a)
\[\int\limits_{-6}^{5}f(x)dx=\int\limits_{-6 }^{-2}f(x)dx+\int\limits_{-2}^{-1}f(x)dx+\int\limits_{-1}^{0}(-f(x))dx\]\[+\int\limits_{0}^{0.5}[-f(x)]dx+\int\limits_{0.5}^{2}f(x)dx+\int\limits_{2}^{5}f(x) dx\]
\[\int\limits_{-2}^{-1 }f(x)dx=\frac{ base \times height }{ 2 }=\frac{ 1\times1 }{ 2 }=\frac{ 1 }{ 2 }\]
\[\int\limits_{0}^{0.5}[-f(x) ]dx=\frac{ base \times height }{ 2 }=\frac{ 0.5 \times 1 }{ 2 }=\frac{ 1 }{ 4 }\]
\[\int\limits_{0.5}^{2}f(x) dx=\frac{ base \times height }{ 2 }=\frac{ 1.5 \times 3 }{ 2 }=\frac{ 9 }{ 4 }\]
\[\int\limits_{2}^{5}f(x) dx=3^2-\frac{ \pi \times 3^2}{ 4 }=9-\frac{ 9 \pi }{ 4 }\] area under the circular arc= area of square-area of quarter circle (r=3)
i have solved without integration. If you want i can solve with integration also. Then you have to find the eq. of two lines and circle then evaluate one by one.
now you substitute for all and find the reqd. result.
for b \[\int\limits_{3}^{5}(2f'(x)+4)dx=2\int\limits_{3}^{5}f'(x) dx+4\int\limits_{3}^{5}dx=2f(x)[3 \rightarrow 5]+4(x)[3 \rightarrow 5]\] eq. of circle is \[(x-5)^2+(y-3)^2=3^2\] \[y-3=\sqrt{9-(x-5)^2}\] when x=3 \[y-3=\sqrt{9-4}\] \[y=3+\sqrt{5}\] when x=5 \[y-3=\sqrt{9-0},y=3+3=6\] so f(x) from 3 to 5 is \[6-(3+\sqrt{5})=3-\sqrt{5}\] assume y= f(x)
\[\int\limits_{3}^{5}(2 f'(x)+4)dx=2(3-\sqrt{5})+4(5-3)=6-2\sqrt{5}+8=14-2\sqrt{5}\]
I don't get it .-.
|dw:1620178074951:dw| let y=f(x) be the curve. Then \[\int\limits_{a}^{b}ydx=\int\limits_{a}^{b}f(x) dx\] It gives the area between ABDC. it is the area under the curve and x-axis between x=a to x=b
if the curve remains above x-axis then reqd. area\[=\int\limits_{a}^{b }ydx\] if it is below x-axis then area\[=\int\limits_{a}^{b}(-y)dx=\int\limits_{a}^{b}(-f(x))dx\]
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