Find the interval in which $f(x) = x + \frac{1}{x}$ is always increasing, $x \neq 0$.
Find the interval in which $f(x) = x + \frac{1}{x}$ is always increasing, $x \neq 0$.
Show Hint
Solution and Explanation
To determine when the function is increasing, we find the derivative of $f(x)$ and set it greater than zero. Given: \[ f(x) = x + \frac{1}{x} \] Differentiate: \[ f'(x) = \frac{d}{dx} \left( x + \frac{1}{x} \right) = 1 - \frac{1}{x^2} \] Now, for the function to be increasing, we need: \[ f'(x) > 0 \] \[ 1 - \frac{1}{x^2} > 0 \] \[ \frac{1}{x^2} < 1 \] This implies: \[ x^2 > 1 \quad \Rightarrow \quad |x| > 1 \] Thus, the function is increasing for: \[ x > 1 \quad \text{or} \quad x < -1 \] Therefore, the function is always increasing on the intervals \( (-\infty, -1) \cup (1, \infty) \).
Top CBSE CLASS XII Mathematics Questions
- 2, b, c are in A.P. and the range of determinant $\begin{vmatrix}1&1&1\\ 2&b&c\\ 4&b^{2}&c^{2}\end{vmatrix}$ is [2, 16]. Then find range of c is
- A committee of 11 members is to be formed from 8 males and 5 females. Let m denotes the number of ways of selecting committee having atleast 6 males and n denotes the number of ways of selecting atleast 3 females then
Determine whether each of the following relations are reflexive, symmetric, and transitive.
- Relation R in the set A={1,2,3,...13,14} defined as R={(x,y): 3x-y=0}.
- Relation R in the set of N natural numbers defined as R={(x,y): y=x+5 and x<4}.
- Relation R in the set A={1,2,3,4,5,6} defined as R={(x,y): y is divisible by x}.
- Relation R in the set of Z integers defined as R={(x,y): x-y is an integer}
- Relation R in the set of human beings in a town at a particular time given by
- R={(x,y): x and y work at same place}
- R={(x,y): x and y live in the same locality}
- R={(x,y): x is exactly 7 am taller that y}
- R={(x,y): x is wife of y}
- R={(x,y):x is father of y}
Show that the relation R in the set R of real numbers, defined as
R = {(a, b): a ≤ b2 } is neither reflexive nor symmetric nor transitive.Check whether the relation R defined in the set {1, 2, 3, 4, 5, 6} as
R = {(a, b): b = a + 1} is reflexive, symmetric or transitive.
Top CBSE CLASS XII Differentiation Questions
- If \( x = at, y = \frac{a}{t} \), then \( \frac{dy}{dx} \) is:
- If \( x^{1/3} + y^{1/3} = 1 \), find \( \frac{dy}{dx} \) at the point \( \left( \frac{1}{8}, \frac{1}{8} \right) \).
- Find the local maximum value and local minimum value (whichever exists) for the function \[ f(x) = 4x^2 + \frac{1}{x}, \quad (x \neq 0). \]
- If \( \sqrt{1 - x^2} + \sqrt{1 - y^2} = a(x - y) \), prove that \( \frac{dy}{dx} = \frac{\sqrt{1 - y^2}}{\sqrt{1 - x^2}} \).
- If \( y = (\tan x)^x \), then find \( \frac{dy}{dx} \).
Top CBSE CLASS XII Questions
- 2, b, c are in A.P. and the range of determinant $\begin{vmatrix}1&1&1\\ 2&b&c\\ 4&b^{2}&c^{2}\end{vmatrix}$ is [2, 16]. Then find range of c is
- A boy of mass 50 kg is standing at one end of a, boat of length 9 m and mass 400 kg. He runs to the other, end. The distance through which the centre of mass of the boat boy system moves is
- A capillary tube of radius r is dipped inside a large vessel of water. The mass of water raised above water level is M. If the radius of capillary is doubled, the mass of water inside capillary will be
- A circular disc is rotating about its own axis. An external opposing torque 0.02 Nm is applied on the disc by which it comes rest in 5 seconds. The initial angular momentum of disc is
- A circular disc is rotating about its own axis at uniform angular velocity \(\omega.\) The disc is subjected to uniform angular retardation by which its angular velocity is decreased to \(\frac {\omega}{2}\) during 120 rotations. The number of rotations further made by it before coming to rest is