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Mark the Correct Alternative in the Following Question: Let F : R → R Be Defined as F(X) = ⎧ ⎨ ⎩ 2 X , I F X > 3 X 2 , I F 1 < X ≤ 3 3 X , I F X ≤ 1 Then, Find F( − 1) + F(2) + F(4)

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प्रश्न

Mark the correct alternative in the following question:
Let f : R→ R be defined as, f(x) =  \[\begin{cases}2x, if x > 3 \\ x^2 , if 1 < x \leq 3 \\ 3x, if x \leq 1\end{cases}\] 

Then, find f( \[-\]1) + f(2) + f(4)

 

विकल्प

  • 14    

  • 5       

  • none of these

MCQ
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उत्तर

\[We have, \] 
\[f\left( x \right) = \begin{cases}2x, if x > 3 \\ x^2 , if 1 < x \leq 3 \\ 3x, if x \leq 1\end{cases}\] 
\[Now, \] 
\[f\left( - 1 \right) + f\left( 2 \right) + f\left( 4 \right)\] 
\[ = 3\left( - 1 \right) + 2^2 + 2\left( 4 \right)\] 
\[ = - 3 + 4 + 8\] 
\[ = 9\]

Hence, the correct alternative is option (a).

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अध्याय 2: Functions - Exercise 2.6 [पृष्ठ ७९]

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आर.डी. शर्मा Mathematics Volume 1 and 2 [English] Class 12
अध्याय 2 Functions
Exercise 2.6 | Q 51 | पृष्ठ ७९

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