If (cos θ + sec θ) = 5/2, then (cos2 θ + sec2 θ) = ?
Given: cos θ + sec θ = 5/2
Squaring both sides, we get:
cos2 θ + sec2 θ + 2 cos θ sec θ = 25/4
cos2 θ + sec2 = (25/4) – 2 cos θ sec θ
= 25/4 – 2
= (25 – 8)/4
= 17/4