5. Continuity and Differentiation
normal

Mean value theorem $f(b) -f(a) = (b -a) f '(x_1);$ from $a < x_1 < b,$ if $f(x) = 1/x$ then $x_1 = ?$

A

$\sqrt {ab}$

B

$\frac{{2ab}}{{a + b}}$

C

$\frac{{a + b}}{{2}}$

D

$\frac{{b - a}}{{b + a}}$

Solution

$f^{\prime}(x)=\frac{f(b)-f(a)}{b-a}$

$\frac{-1}{x^{2}}=\frac{\frac{1}{b}-\frac{1}{a}}{b-a}$

$\frac{{ – 1}}{{{x^2}}} = \frac{{a – b}}{{ab(b – a)}}$

$\frac{1}{x^{2}}=\frac{1}{a b}$

Standard 12
Mathematics

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.