If  \( \alpha \) is a positive acute angle and \( 2sin\alpha+15cos^2\alpha=7, \)  then the value of \( cot\alpha \)  is-

Find the value of following equation:

${\left(\sec \varnothing -\tan \varnothing \right)}^2{\left(1+\sin \varnothing \right)}^2÷{\sin }^2 \varnothing =?$

If $3\sin \theta =2{\cos }^2\theta , 0^0<\theta <{90}^0$. Then the value of $({\tan }^2\theta +se{c}^2\theta -\cos e{c}^2\theta )$ is: