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The area (in sq. units) bounded by the parabola y = x^2 -1 , the tangent at the point (2,3) to it and y-axis is:

  • Option 1)

    \frac{8}{3}

  • Option 2)

    \frac{32}{3}

  • Option 3)

    \frac{56}{3}

  • Option 4)

    \frac{14}{3}

Answers (1)

best_answer

 

Introduction of area under the curve -

The area between the curve y= f(x),x axis and two ordinates at the point  x=a\, and \,x= b\left ( b>a \right ) is given by

A= \int_{a}^{b}f(x)dx=\int_{a}^{b}ydx

- wherein

 

 

Area along x axis -

Let y_{1}= f_{1}(x)\, and \, y_{2}= f_{2}(x) be two curve then area bounded between the curves and the lines

x = a and x = b is

\left | \int_{a}^{b} \Delta y\, dx\right |= \left | \int_{a}^{b}\left ( y_{2}-y_{1} \right ) dx\right |

 

- wherein

Where \Delta y= f_{2}\left ( x \right )-f_{1}(x)

Tangent to the parabola y=x^{2}-1 at \left ( 2,3 \right ) is yy_{1}=2a\left ( x+4 \right )

Required shaded area

=ar\left ( \bigtriangleup ABC \right )-\int_{-1}^{3}\sqrt{y+1}dy

=\frac{1}{2}\times8\times 2-\frac{2}{3}\left ( y+1 \right )^{\frac{3}{2}}|_{-1}^{3}

=\frac{8}{3}sq.unit.


Option 1)

\frac{8}{3}

Option 2)

\frac{32}{3}

Option 3)

\frac{56}{3}

Option 4)

\frac{14}{3}

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