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Question

If $f '(x) = e^x$ and $f(0) = 5$, then from Mean Value Theorem, the value of $f (1)$ lies between

The correct answer is
6 and $(5 + e)$

Mean Value Theorem Application

The Mean Value Theorem (MVT) states that if a function $f$ is continuous on a closed interval $[a, b]$ and differentiable on the open interval $(a, b)$, then there exists at least one number $c$ in $(a, b)$ such that: $ f'(c) = \frac{f(b) - f(a)}{b - a} $

Applying MVT to the Problem

We are given $f'(x) = e^x$, $f(0) = 5$, and we need to find the interval for $f(1)$. Here, $a = 0$ and $b = 1$. Using the MVT formula:

$ f'(c) = \frac{f(1) - f(0)}{1 - 0} $

Substituting the known values:

$ e^c = \frac{f(1) - 5}{1} $ $ e^c = f(1) - 5 $

Rearranging to solve for $f(1)$:

$ f(1) = 5 + e^c $

Determining the Range for $f(1)$

According to the MVT, the value $c$ must lie in the open interval $(a, b)$, which is $(0, 1)$. So, $0 < c < 1$. Since the exponential function $f(x) = e^x$ is an increasing function, applying it to the inequality $0 < c < 1$ gives:

$ e^0 < e^c < e^1 $ $ 1 < e^c < e $

Now, substitute this range of $e^c$ into the expression for $f(1)$:

$ f(1) = 5 + e^c $

Adding 5 to all parts of the inequality $1 < e^c < e$:

$ 5 + 1 < 5 + e^c < 5 + e $ $ 6 < f(1) < 5 + e $

Therefore, the value of $f(1)$ lies between 6 and $(5 + e)$.

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Important Questions from Mean Value Theorem

  1. A series expansion for the function sin θ is

  2. If f is the derivative of some function on [a, b], then there exists a number c in (a, b) such that Integral of f with respect to x =

  3. Which condition is not required in checking for Taylor's theorem?

  4. What is the interval of Taylor series expansion of tan(x)?
  5. According to the Mean Value Theorem, for a continuous function f(x) in the interval [a, b], there exists a value ξ in this interval such that \(\mathop \smallint \limits_a^b f\left( x \right)dx =\)

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