If $$ {cot A={n\over{n+1}}}$$ and $$ {cot B={1\over{2n+1}}}$$ then what is the value of cot (A + B)?

In ΔABC θ is an acute angle and tanθ is equal to three times of cotθ. Find the value of $$ {sin^{2}θ+cosec^{2}θ-{1\over 2}cot^{2}θ}$$.

In the given figure BC=15 cm and Sin B=4/5.  then find out the value of AB?

If 1 + sin² A = 3 sin A cos A, then what are the possible values of tan A?

If  $$ {cosAcotA \over( 1 - sinA ) }=x $$ then the value of x is : 

Find the value of $$ {\sqrt{(cos^{2}20°+cos^{2}70°)}}$$

Find the value of $$\left({1\over {sin 60°}} \right)^{2} + (cos 30°)^{2} \over(tan 45°)^{2}$$.

If sec -5π/4 = x, then  the value   of x is