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Explain solution RD Sharma Class 12 Chapter 20 Areas of Bounded Regions exercise 20.3 question 38 Maths.

Answers (1)

Answer:

\frac{9}{2} sq. Units

Hints:

Use concept .

Given:

x^2=y is a parabola line y=x+2

Solution: x^2=y  is a upward parabola line y=x+2

They meet at pts (2,4) and (-1,1)

By solving the equation,

\begin{aligned} &x^{2}=y, y=x+2 \\ &\Rightarrow x^{2}-x-2=0 \\ &\Rightarrow x=2 \text { or }-1 \\ &\Rightarrow x=4 \text { or } 1 \end{aligned}

 Required area

= \int_{-1}^{2} Area of line - \int_{-1}^{2} Area of parabola

 

\begin{aligned} &=\int_{-1}^{2}(x+2) d x-\int_{-1}^{2} x^{2} d x \\ &=\left[\frac{x^{2}}{2}\right]_{-1}^{2}+[2 x]_{-1}^{2}-\left[\frac{x^{3}}{3}\right]_{-1}^{2} \\ &=\frac{4}{2}-\frac{(-1)^{2}}{2}+2 * 2-(2 *-1)-\left(\frac{2^{3}}{3}-\frac{(-1)^{3}}{3}\right) \\ &=2-\frac{1}{2}+4+2-\left(\frac{8}{3}+\frac{1}{3}\right) \\ &=8-\frac{1}{2}-3=5-\frac{1}{2}=\frac{9}{2} \text { sq.units } \end{aligned}

 

 

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