- #1
Saitama
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Homework Statement
If ##\beta## is such that ##\sin 2\beta≠0##, then show that the expression ##\displaystyle \frac{x^2+2x\cos\alpha+1}{x^2+2x\cos\beta+1}## (x real) always lies between ##\cos^2\alpha/\cos^2\beta## and ##\sin^2\alpha/\sin^2\beta##.
Homework Equations
The Attempt at a Solution
I can rewrite the given expression to
[tex]\frac{(x+\cos\alpha)^2+\sin^2\alpha}{(x+\cos\beta)^2+\sin^2\beta}[/tex]
What should I do next?