- Home
- Standard 12
- Mathematics
1.Relation and Function
hard
જો વિધેય $f(x)=\log _e\left(4 x^2+11 x+6\right)+\sin ^{-1}(4 x+3)+\cos ^{-1}\left(\frac{10 x+6}{3}\right)$ નો પ્રદેશ $(\alpha, \beta]$ હોય, તો $36|\alpha+\beta|=......$
A
$63$
B
$45$
C
$72$
D
$54$
(JEE MAIN-2023)
Solution
$f(x)=\ln \left(4 x^2+11 x+6\right)+\sin ^{-1}(4 x+3)$
$+\cos ^{-1}\left(\frac{10 x+6}{3}\right)$
$\text { (i) } 4 x^2+11 x+6 > 0$
$4 x^2+8 x+3 x+6 > 0$
$(4 x+3)(x+2) > 0$
$x \in(-\infty,-2) \cup\left(-\frac{3}{4}, \infty\right)$
$\text { (ii) } 4 x+3 \in[-1,1]$
$x \in[-1,-1 / 2]$
$\text { (iii) } \frac{10 x+6}{3} \in[-1,1]$
$x \in\left[-\frac{9}{10},-\frac{3}{10}\right]$
$x \in\left(-\frac{3}{4},-\frac{1}{2}\right]$
$\alpha+\beta=-\frac{5}{4}$
$36|\alpha+\beta|=45$
Standard 12
Mathematics