Question
Evaluate the following limit:
$\lim\limits_{\text{x}\rightarrow0}(\cos\text{x}+\sin\text{x})^{\frac{1}{\text{x}}}$

Answer

$\lim\limits_{\text{x}\rightarrow0}(\cos\text{x}+\sin\text{x})^{\frac{1}{\text{x}}}$
$=\ \lim\limits_{\text{x}\rightarrow0}(1+(\cos\text{x}+\sin\text{x}-1))^{\frac{1}{\text{x}}}$
$=\text{e}^{\lim\limits_{\text{x}\rightarrow0}\frac{(\cos\text{x}+\sin\text{x}-1)}{\text{x}}}$
$=\text{e}^{\lim\limits_{\text{x}\rightarrow0}\frac{(\sin\text{x}-(1-\cos\text{x}))}{\text{x}}}$
$=\text{e}^{\lim\limits_{\text{x}\rightarrow0}\frac{\big(\sin\text{x}-2\sin^2\big(\frac{\text{x}}{2}\big)\big)}{\text{x}}}$
$=\text{e}^{\lim\limits_{\text{x}\rightarrow0}\frac{\sin\text{x}}{\text{x}}-\lim\limits_{\text{x}\rightarrow0}\frac{2\sin\big(\frac{\text{x}}{2}\big)\sin\big(\frac{\text{x}}{2}\big)}{2\big(\frac{\text{x}}{2}\big)}}$
$=\text{e}^{\lim\limits_{\text{x}\rightarrow0}\frac{\sin\text{x}}{\text{x}}-\lim\limits_{\text{x}\rightarrow0}\frac{2\sin\big(\frac{\text{x}}{2}\big)\sin\big(\frac{\text{x}}{2}\big)}{\big(\frac{\text{x}}{2}\big)}}$
$=\text{e}^{1-0}$
$=\text{e}$

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

Show the following quadratic equation by factorization method:
$\sqrt{3}\text{x}^2-\sqrt{2 }\text{x}+2\sqrt{3}=0$
Find the coordinates of the foci, the vertices, the length of major axis, the minor axis, the eccentricity and the length of the latus rectum of the ellipse.
$\frac{{{x^2}}}{{36}} + \frac{{{y^2}}}{{16}} = 1$
Differentiate the following function with respect to x:

$\frac{2^\text{x}\cot\text{x}}{\sqrt{\text{x}}}$

If $\sin\text{A}=\frac{4}{5}$ and $\cos\text{B}=\frac{5}{13}$ Where $0<\text{A},\text{B}<\frac{\pi}{2},$ find the value of the following:
Find the equation of the parabola whose focus is (5, 2) and having vertex at ( 3, 2).
Find the derivative of $\frac{2}{{x + 1}} - \frac{{{x^2}}}{{3x - 1}}$
In a survey it was found that 21 people liked product A, 26 liked product B and 29 liked product C. If 14 people liked products A and B, 12 people liked products C and A, 14 people liked products B and C and 8 liked all the three products. Find how many liked product C only?
The means and standard deviations of heights ans weights of 50 students of a class are as follows:
  Weights Heights
Mean 63.2kg 63.2 inch
Standard deviation 5.6kg 11.5 inch
Which shows more variability, heights or weights?
Find the equation of the straight line which joints the point $(3,5)$ to the point of intersection of lines $4 x+y=1$ and $7 x-3 y-35=0$. Prove that this line is at equal distance from origin and point $(8,34)$.
In a class of 35 students, 24 like to play cricket and 16 like to play football. Also, each student likes to play at least one of the two games. How many students like to play both cricket and football?