Sec squared theta + 10 theta is equals to 5 upon 6.6 sec theta tan theta

Question

Sec theta + 10 theta is equals to 5.6

Answer 1

sec^2(T+10T)= 5.6
sec^2(11T) = 5.6 = 56/10 = 28/5
cos^2(11T) = 5/28
cos^2(X) = 5/28 cos^2(x) - 5/28 = 0
[ cos X + sqrt(5/28) ] [ cos X - sqrt(5/28) ] = 0
cos X = -sqrt(5/28) or cos x = sqrt(5/28)
X= inverse-cosine( sqrt(5/28)) = 65
T = 65/11
or
X=inverse-cosine(-sqrt(5/28)) = 115
T = 115/11