If f(x)=∣∣∣∣sin xsin asin bcos xcos acos btan xtan atan b∣�

1.	If f(x)=∣∣∣∣sin xsin asin bcos xcos acos btan xtan atan b∣∣∣∣, where 0<a<b<π2 then the equation f′(x)=0 has in the interval (a,b)
Answer» If $f (x) = ∣ ∣∣ ∣ \begin{matrix} s i n x & s i n a & s i n b c o s x & c o s a & c o s b t a n x & t a n a & t a n b \end{matrix} ∣ ∣∣ ∣,$ where $0 < a < b < \frac{π}{2}$ then the equation $f^{'} (x) = 0$ has in the interval $(a, b)$

If f(x)=∣∣∣∣sin xsin asin bcos xcos acos btan xtan atan b∣∣∣∣, where 0<a<b<π2 then the equation f′(x)=0 has in the interval (a,b)

Answer»

If $f (x) = ∣ ∣∣ ∣ \begin{matrix} s i n x & s i n a & s i n b c o s x & c o s a & c o s b t a n x & t a n a & t a n b \end{matrix} ∣ ∣∣ ∣,$

where $0 < a < b < \frac{π}{2}$
then the equation
$f^{'} (x) = 0$ has in the interval $(a, b)$