The mean of numbers a, b, 8, 5, 10 is 6 and t | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(D) Given the mean of $a, b, 8, 5, 10$ is $6$: $\frac{a+b+8+5+10}{5} = 6 \implies a+b+23 = 30 \implies a+b = 7$. The variance is $6.80$: $\frac{a^2+b^

Vedclass · Accepted Answer

$\operatorname{Tan}^{-1} \frac{7}{11}$

Vedclass · Answer

(D) Given the mean of $a, b, 8, 5, 10$ is $6$: $\frac{a+b+8+5+10}{5} = 6 \implies a+b+23 = 30 \implies a+b = 7$. The variance is $6.80$: $\frac{a^2+b^2+8^2+5^2+10^2}{5} - (6)^2 = 6.80$. $\frac{a^2+b^2+64+25+100}{5} - 36 = 6.80$. $\frac{a^2+b^2+189}{5} = 42.80$. $a^2+b^2+189 = 214 \implies a^2+b^2 = 25$. Since $(a+b)^2 = a^2+b^2+2ab$,we have $7^2 = 25 + 2ab \implies 49 = 25 + 2ab \implies 2ab = 24 \implies ab = 12$. We need to find $\operatorname{Tan}^{-1} \frac{1}{a} + \operatorname{Tan}^{-1} \frac{1}{b} = \operatorname{Tan}^{-1} \left( \frac{\frac{1}{a} + \frac{1}{b}}{1 - \frac{1}{ab}} \right) = \operatorname{Tan}^{-1} \left( \frac{\frac{a+b}{ab}}{1 - \frac{1}{ab}} \right) = \operatorname{Tan}^{-1} \left( \frac{a+b}{ab-1} \right)$. Substituting the values: $\operatorname{Tan}^{-1} \left( \frac{7}{12-1} \right) = \operatorname{Tan}^{-1} \frac{7}{11}$.

The mean of numbers $a, b, 8, 5, 10$ is $6$ and their variance is $6.80$. Then $\operatorname{Tan}^{-1} \frac{1}{a} + \operatorname{Tan}^{-1} \frac{1}{b} =$

Similar Questions

$\lim _{n \rightarrow \infty} \sum_{r=1}^n \cot ^{-1}\left(r^2+\frac{3}{4}\right)=$

If $x=\sin \left(2 \tan ^{-1} 2\right)$ and $y=\sin \left(\frac{1}{2} \tan ^{-1} \frac{4}{3}\right)$,then

Find the maximum value of the expression $\lfloor \tan^{-1} x - \tan^{-1} y \rfloor - \lfloor \sin^{-1} u - \sin^{-1} v \rfloor$,where $\lfloor . \rfloor$ denotes the greatest integer function,and $x, y, u, v$ are independent real variables.

The value of $x$,where $x>0$ and $\tan \left(\sec ^{-1}\left(\frac{1}{x}\right)\right)=\sin \left(\tan ^{-1} 2\right)$ is

If $u = \tan^{-1} \left( \frac{\sqrt{1 + x^2} - 1}{x} \right)$ and $v = 2 \tan^{-1} x$,then $\frac{du}{dv}$ is equal to

Vedclass Test Series

Exam Paper Generator

Online Exam Module