If ${{2}^{n}}=128$ , find the value of $({{2}^{n-1}})({{5}^{n-2}})$

If $\cos {{(x+25)}^{o}}=\sin {{45}^{o}}$, find the value of x

if $\tan x=1$evaluate $\sin x+\cos x$ leaving your answer in surd form 

If ${{x}^{o}}$ is obtuse, which of the following is true?

In the diagram, O is the centre of the circle and PQRS is a cyclic quadrilateral. Find the value of x   

In the figure  $\left| PX \right|=\left| XQ \right|,\text{ }\left| PQ \right|\parallel \left| YZ \right|$ and $XY\parallel QR$>What is the ratio of the area of XYZQ to $\Delta YZR$ ?

The angle of a quadrilateral are ${{(x+10)}^{o}},2{{y}^{o}},{{90}^{o}}\text{ and (100}-y{{)}^{o}}$. Find y in term of x

In the diagram, $PQ\parallel RS,\text{ }QU\parallel PT\text{ and }\angle PSR={{42}^{{}^\circ }}$. Find the angle x

In the figure shown, PQS is a straight line. What is the value of $\angle PRQ$