Question

1+cos2theta+cos6theta/cos4theta

Answer 1

We hav 1 + $\frac{cos 2 \alpha + cos6\alpha  }{cos4\alpha }$

Now

$\frac{cos 2 (\frac{6\alpha +2\alpha   }{2}) + cos(\frac{6\alpha -2\alpha   }{2})  }{cos4\alpha }$

1 + 2 cos 2 $\alpha$

1+291-2sin^2$\alpha$

1+2 - 4sin^2$\alpha$

3 - 4 sin^2$\alpha$

Here is the answer

Hope You Understand  

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