Question

if cos(teeta-alpha ),costeeta ,cos (teeta + alpha ) are in hp then cos theeeta -sec alpha /2=?​

Answer 1

Step-by-step explanation:

If three numbers

are in H.P., then,<br>

<br> As,

are in H.P.,<br>

<br>

<br>

<br>

<br>

<br>

<br>

<br>

<br>

<br>

<br>

<br>

<br>