MCQ
Choose the correct answer.
The minimum value of $4^{\text{x}}+4^{1-\text{x}},\text{x}\in\text{R}$ is:
  • A
    2
  • B
    4
  • C
    1
  • D
    0

Answer

  1. 6

Solution:

We know that $\text{AM}\geq\text{GM}$

$\therefore\ \frac{4^\text{x}+4^{1-\text{x}}}{2}\geq\sqrt{4^\text{x}.4^{1-\text{x}}}\Rightarrow4^\text{x}+4^{1-\text{x}}\geq2\sqrt{4^{\text{x}+1-\text{x}}}$

$4^\text{x}+4^{1-\text{x}}\geq2.2\Rightarrow4^\text{x}+4^{1-\text{x}}\geq4$

Hence, the correct option is (b).

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Choose the correct answer.

The equations of the lines passing through the point (1, 0) and at a distance $\frac{\sqrt{3}}{2}$ from the origin, are

If $3\sin\text{x}+4\cos\text{x}=5,$ then $4\sin\text{x}-3\cos\text{x}=$

  1. $0$

  2. $5$

  3. $1$

  4. None of these

The number of parallelograms that can be formed from a set of four parallel lines intersecting another set of three parallel lines is:
The probability that a leap year will have 53 Fridays or 53 Saturdays is:
  1. $\frac{2}{7}$
  2. $\frac{3}{7}$
  3. $\frac{4}{7}$
  4. $\frac{1}{7}$

The point represented by the complex number 2 - i is rotated about origin through an angle $\frac{\pi}{2}$ in the clockwise direction, the new position of point is:

  1. 1 + 2i
  2. -1 - 2i
  3. 2 + i
  4. -1 + 2i
$ \lim_\limits{\text{x}→1} \sqrt{x +1) (2x - 3)} \sqrt{2x3 + x -3}$ is:
The equation of the circle passing through the point (1, 1) and having two diameters along the pair of lines x2 - y2 - 2x + 4y - 3 = 0, is:
  1. x2 + y2 - 2x - 4y + 4 = 0
  2. x2 + y2 + 2x + 4y - 4 = 0
  3. x2 + y2 - 2x + 4y + 4 = 0
  4. None of these
The symbol of an inequality :

What is the value of the limit $\text{f}(\text{x}) = \frac{\text{sin}^2\text{x}+2\sqrt{\text{sinx}}}{\text{x}^2−4\text{x}}$ if x approaches 0?

let x1, x2, ...,xn be n observations and $\overline{\text{X}}$ be their arithmetic mean. The standard deviation is given by:
  1. $\sum\limits^\text{n}_{\text{i}=1}\Big(\text{x}_\text{i}-\overline{\text{X}}\Big)^2$
  2. $\frac{1}{\text{n}}\sum\limits^\text{n}_{\text{i}=1}\Big(\text{x}_\text{i}-\overline{\text{X}}\Big)^2$
  3. $\sqrt{\frac{1}{\text{n}}\sum^\text{n}_{\text{i}=1}\Big(\text{x}_\text{i}-\overline{\text{X}}\Big)^2}$
  4. $\sqrt{\frac{1}{\text{n}}\sum^\text{n}_{\text{i}=1}\text{x}_\text{i}^2-\overline{\text{X}}^2}$