$$ sin^2 5° + sin^2 10°+sin^2 15°+.....sin^2 85°+sin^2 90°$$ is equal to

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

If x cos²30⁰. sin60⁰=$${tan^2{45}^0.sec60^0}\over cosec\ 60^0$$ then the value of x : 

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

If $$ {\sqrt{3}\ CosA=SinA}$$ then what is the value of Cot A?

If A and B are acute angles and Sec A =3; Cot B=4, then the value of $$ {Cosec^{2}A}+Sin^{2}B\over {Cot^{2}A+Sec^{2}B}$$ is:

If cosec 39°= x, the value of $$ {1\over {cosec^{2}{51°}}} +sin^{2} 39^{°}+tan^{2}{51^{°}}-{1\over {sin^{2}{51^{°}}}{Sec^{2}{39^{°}}}}$$ is-