Question
Differentiate the following from the first principle$\sqrt{\sin\text{2x}}$

Answer

We have,$\text{f}(\text{x})=\sqrt{\sin\text{2x}}$
$\because\text{f}'(\text{x})=\lim_\limits{\text{h}\rightarrow0}\frac{\text{f}(\text{x}+\text{h})-\text{f}(\text{x})}{\text{h}}$
$=\lim_\limits{\text{h}\rightarrow0}\frac{\sqrt{\sin2(\text{x}+\text{h})}-\sqrt{\sin\text{2x}}}{\text{h}}$
Multiplying numerator and denominator by $\Big(\sqrt{\sin2(\text{x}+\text{h})}+\sqrt{\sin\text{2x}}\Big)$
$\lim_\limits{\text{h}\rightarrow0}\frac{\sqrt{\sin2(\text{x}+\text{h})}-\sqrt{\sin\text{2x}}}{\text{h}}\times\frac{\sqrt{\sin2(\text{x}+\text{h})}+\sqrt{\sin\text{2x}}}{\sqrt{\sin2(\text{x}+\text{h})}+\sqrt{\sin2\text{x}}}$
$=\lim_\limits{\text{h}\rightarrow0}\frac{\sin(\text{2x}+\text{2h})-\sin\text{2x}}{\Big(\sqrt{\sin(\text{2x}+\text{2h})}+\sqrt{\sin2\text{x}}\Big)}$ $\Big[\sin\text{c}-\sin\text{d}=2\cos\frac{\text{c}+\text{d}}{2}\sin\frac{\text{c}-\text{d}}{2}\Big]$
$\lim_\limits{\text{h}\rightarrow0}\frac{2\cos(\text{2x}+\text{h})\times\sin\text{h}}{\text{h}}\times\frac{1}{\sqrt{\sin(\text{2x}+\text{2h})}+\sqrt{\sin\text{2x}}}$
$=\frac{2\cos\text{2x}}{2\sqrt{\sin\text{2x}}}$
$=\frac{\cos\text{2x}}{\sqrt{\sin\text{2x}}}$

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

Evaluate the following limit:
$\lim\limits_{\text{x}\rightarrow\pi}\frac{1+\cos\text{x}}{\tan^2\text{x}}$
Prove that the radii of the circles $x^2 + y^2 = 1, x^2 + y^2 - 2x − 6y - 6 = 0$ and $x^2 + y^2 - 4x - 12y - 9 = 0$ are in A.P.
Two fair dice are thrown. State the sample space and write the favourable outcomes for the following events.

A : Sum of numbers on two dice is divisible by 3 or 4.

B : The sum of numbers on two dice is 7.

C : Odd number on the first die.

D : Even number on the first die.

E: Check whether events A and B are mutually exclusive and exhaustive.

F: Check whether events C and D are mutually exclusive and exhaustive.

Find the sum of the following series to $n$ terms:
$1.2.5 + 2.3.6 + 3.4.7 + ...$
Discuss the continuity and differentiability of :

f(x) = (2x + 3) |2x + 3| at x = $\frac{-3}{2}$

For three events A, B and C, we know that A and C are independent, B and C are

independent, $A$ and $B$ are disjoint, $P(A \cup C)=\frac{2}{3}, P(B \cup C)=\frac{3}{4}, P(A \cup B \cup C)=\frac{11}{12}$. Find

P(A), P(B) and P(C).

Determine the domain and range of the relation R defined by:
$\text{R}=\{(\text{x, x,}+5):\text{x}\in\{0,1,2,3,4,5\}\}$
Solve the following systems of linear inequations graphically:
$2\text{x}+3\text{y}\leq6,\text{x}+4\text{y}\leq4,\text{x}\geq0,\text{y}\geq0$
Express the following complex numbers in the form $\text{r}(\cos\theta+\text{i}\sin\theta):$
$1-\sin\alpha+\text{i}\cos\alpha$
Prove that the centres of the three circles $x^2 + y^2 - 4x - 6y - 12 = 0, x^2 + y^2 + 2x + 4y - 10 = 0$ and $x^2 + y^2 - 10x - 16y - 1 = 0$ are collinear.