Question
The Function $\text{f}(\text{x})=\frac{\lambda+\sin\text{x}+2\cos\text{x}}{\sin\text{x}+\cos\text{x}}$ is increasing, if:
  1. $\lambda<1$
  2. $\lambda>1$
  3. $\lambda<2$
  4. $\lambda>2$

Answer

  1. $\lambda>2$

Solution:

$\text{f}(\text{x})=\frac{\lambda+\sin\text{x}+2\cos\text{x}}{\sin\text{x}+\cos\text{x}}$

$\Rightarrow\text{f}(\text{x})=(\lambda-2)\sin^2\text{x}+(\lambda-2)\cos^2\text{x}>0$

Using identity $\Rightarrow\lambda-2>0$

$\Rightarrow\lambda>2$

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

A coin is tossed $m + n$ times, where $m \ge n.$ The probability of getting at least $m$ consecutive heads is
A function $f(x)$ satisfies $f\left( x \right) = f\left( {\frac{c}{x}} \right)$ for some real number $c\left( {c > 1} \right)$ and $\forall\, x > 0$. If $\int\limits_1^{\sqrt c } {\frac{{f\left( x \right)}}{x}} dx = 3$ , then the value of $\int\limits_1^c {\frac{{f\left( x \right)}}{x}} dx$ is
$\int\limits^\pi_0\sqrt{\frac{1-\text{x}}{1+\text{x}}}\text{ dx}=$
  1. $\sqrt{1-\pi^2}-1$
  2. $\frac{\pi}{2}-1$
  3. $\frac{\pi}{2}+1$
  4. ${\pi}+{1}$
If $f(x)$ is a continuous and differentiable function satisfying $f(x).f(f(x)) = x^2 + 1, \, f(1) = 2, \,f'(1) = k$, then the value of $f'(2)$ is
The order of the differential equation whose general solution is given by
$
y=\left(C_1+C_2\right) \cos \left(x+C_3\right)-C_4 e^{x+C_5}
$
where $C_1, C_2, C_3, C_4, C_5$ are arbitrary constants, is
If the vectors $\vec{a}=\lambda \hat{i}+\mu \hat{j}+4 \hat{k}, \vec{b}=2 \hat{i}+4 \hat{j}-2 \hat{k}$ and $\vec{c}=2 \hat{i}+3 \hat{j}+\hat{k}$ are coplanar and the projection of $\vec{a}$ on the vector $\vec{b}$ is $\sqrt{54}$ units, then the sum of all possible values of $\lambda+\mu$ is equal to
Let $\int_0^x \sqrt{1-\left(y^{\prime}(t)\right)^2} d t=\int_0^x y(t) d t, 0 \leq x \leq 3, y \geq 0$, $\mathrm{y}(0)=0$. Then at $\mathrm{x}=2, \mathrm{y}^{\prime \prime}+\mathrm{y}+1$ is equal to :
$\int_0^{1/2} {\frac{{x{{\sin }^{ - 1}}x}}{{\sqrt {1 - {x^2}} }}\,dx = } $
The perpendicular distance of the point P(1, 2, 3) from the line $\frac{\text{x}-6}{3}=\frac{\text{y}-7}{2}=\frac{\text{z}-7}{-2}$ is:
  1. 7
  2. 5
  3. 0
  4. None of these 
What must be the matrix $X$ if $2X + \left[ {\begin{array}{*{20}{c}}1&2\\3&4\end{array}} \right] = \left[ {\begin{array}{*{20}{c}}3&8\\7&2\end{array}} \right]$