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solve trig equation involving a translation in given internval. with worked solutions

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Trig equation with a translation

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\\begin{align}

sin \\left(x-\\frac{\\pi}{2} \\right) & =\\var{a} \\\\\\\\
\\left(x-\\frac{\\pi}{2} \\right) & = sin^{-1}(\\var{a})=\\var{x1n} \\\\\\\\
\\text{for $sinx$ you can find a second solution by going $\\pi-x_1$} \\\\\\\\
\\left(x-\\frac{\\pi}{2} \\right) & = \\pi-\\var{x1n}=\\var{x2n} \\\\\\\\

\\end{align}

\n

As the range of solution goes down to $-2\\pi$ you can find two more angles by taking away $2\\pi$ from the first two angles.

\n

\\begin{align}

x_3 &=\\var{x1n}-2\\pi=\\var{x3n} \\\\\\\\
x_4 &=\\var{x2n}-2\\pi=\\var{x4n}

\\end{align}

\n

In ascending order your three solutions so far are

\n

\\begin{align}
\\left(x-\\frac{\\pi}{2} \\right) & =\\var{x3n} \\text{   or   } \\var{x4n} \\text{   or   } \\var{x1n} \\text{   or   } \\var{x2n}
\\end{align}

\n

To find $x$ all you need to do now is add $\\frac{\\pi}{2}$

\n

\\begin{align}
x=\\var{x3} \\text{   or   } \\var{x4} \\text{   or   } \\var{x1} \\text{   or   } \\var{x2}
\\end{align}

\n

To 3 significant figures this gives

\n

\\begin{align}
x=\\var{x3_3}^c \\text{   or   } \\var{x4_3}^c \\text{   or   } \\var{x1_3}^c \\text{   or   } \\var{x2_3}^c
\\end{align}

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Solve $sin \\left(x-\\frac{\\pi}{2} \\right)=\\var{a}$ between $-2\\pi<x<2\\pi$

\n

\n

Give your answers in radians in ascending order and to 3 significant figures.

\n

\n

$x_1$=[[2]]

\n

$x_2$=[[3]]

\n

$x_3$=[[0]]

\n

$x_4$=[[1]]

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