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Question Number 102444 by bemath last updated on 09/Jul/20
find the area bounded the  curves y^2 = 36+12x and   y^2 =16−8x
$${find}\:{the}\:{area}\:{bounded}\:{the} \\ $$$${curves}\:{y}^{\mathrm{2}} =\:\mathrm{36}+\mathrm{12}{x}\:{and}\: \\ $$$${y}^{\mathrm{2}} =\mathrm{16}−\mathrm{8}{x}\: \\ $$
Answered by bemath last updated on 09/Jul/20
⇔ ((y^2 −36)/(12)) = ((16−y^2 )/8)  (y^2 /(12))−3 = 2−(y^2 /8)  ((5y^2 )/(24)) − 5 = 0 ⇒Δ=((4.5.5)/(24)) = ((25)/6)  Area = ((Δ(√Δ))/(6.a^2 )) = ((((25)/6).(5/( (√6))))/(6.(((25)/(24^2 )))))  =((125)/(6(√6))) × ((24.24)/(6.25)) = ((80)/( (√6)))  = ((40(√6))/3) .
$$\Leftrightarrow\:\frac{{y}^{\mathrm{2}} −\mathrm{36}}{\mathrm{12}}\:=\:\frac{\mathrm{16}−{y}^{\mathrm{2}} }{\mathrm{8}} \\ $$$$\frac{{y}^{\mathrm{2}} }{\mathrm{12}}−\mathrm{3}\:=\:\mathrm{2}−\frac{{y}^{\mathrm{2}} }{\mathrm{8}} \\ $$$$\frac{\mathrm{5}{y}^{\mathrm{2}} }{\mathrm{24}}\:−\:\mathrm{5}\:=\:\mathrm{0}\:\Rightarrow\Delta=\frac{\mathrm{4}.\mathrm{5}.\mathrm{5}}{\mathrm{24}}\:=\:\frac{\mathrm{25}}{\mathrm{6}} \\ $$$${Area}\:=\:\frac{\Delta\sqrt{\Delta}}{\mathrm{6}.{a}^{\mathrm{2}} }\:=\:\frac{\frac{\mathrm{25}}{\mathrm{6}}.\frac{\mathrm{5}}{\:\sqrt{\mathrm{6}}}}{\mathrm{6}.\left(\frac{\mathrm{25}}{\mathrm{24}^{\mathrm{2}} }\right)} \\ $$$$=\frac{\mathrm{125}}{\mathrm{6}\sqrt{\mathrm{6}}}\:×\:\frac{\mathrm{24}.\mathrm{24}}{\mathrm{6}.\mathrm{25}}\:=\:\frac{\mathrm{80}}{\:\sqrt{\mathrm{6}}} \\ $$$$=\:\frac{\mathrm{40}\sqrt{\mathrm{6}}}{\mathrm{3}}\:. \\ $$

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