let f:r-r be a function given by f(x)=x2+2.find f-1(27).

1.	let f:r-r be a function given by f(x)=x2+2.find f-1(27).
Answer» {tex}let\\,{f^{ - 1}}\\left( {27} \\right) = x{/tex}{tex} \\Rightarrow f\\left( x \\right) = 27{/tex}{tex} \\Rightarrow {x^2} + 2 = 27{/tex}{tex} \\Rightarrow {x^2} = 25{/tex}{tex} \\Rightarrow x = \\pm 5{/tex}{tex}Hence{/tex}{tex}{f^{ - 1}}\\left( {27} \\right) = \\left\\{ { - 5,5} \\right\\}{/tex}

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