# if sec theta+tan theta+1= 0,then find sec theta -tan theta

sec theta + tan theta = -1 ..............(1)

we know that sec

^{2}- tan

^{ 2}= 1

therfore (sec+tan)(sec-tan) = 1

-1(sec-tan) = 1..........(from 1)

sec-tan=1/-1

therefore sec-tan=-1

Hope it helps.......Cheers!!!