Question bank/JEE Main/Mathematics

JEE MainMathematicsEasyDefinite Integration

Let f: R →\rightarrow R be a twice differentiable function
satisfying f(2) = - 1, f '(2) = 4 and

∫23\mspace2mu(3−x)f′′(x)dx=7\int_{2}^{3}\mspace{2mu}(3 - x)f^{''}(x)dx = 7 the value of f(3) is
equal to

Show answer and solution
∵∫23\mspace2mu(3−x)f′′(x)dx=7\because\int_{2}^{3}\mspace{2mu}(3 - x)f^{''}(x)dx = 7
⇒[(3−x)f′(x)]23−∫23\mspace2mu(−1)f′(x)dx=7\Rightarrow \left\lbrack (3 - x)f^{'}(x) \right\rbrack_{2}^{3} - \int_{2}^{3}\mspace{2mu}( - 1)f^{'}(x)dx = 7
0−f′(2)+∫23\mspace2muf′(x)dx=70 - f^{'}(2) + \int_{2}^{3}\mspace{2mu} f^{'}(x)dx = 7
f(3) = 10

Source: Grass-G / M-13 Mathematics Paper 4 Nov.docx

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