How many pairs of (x, y) can be chosen from the set {2, 3, 6, 8, 9} such that x/y + y/x = 2, where x ≠ y?

If 6 + 8tanθ = secθ and 8 – 6tanθ = ksecθ, then what is…

What is (1 + cotθ – cosecθ)(1 + tanθ + secθ) equal to?

If secθ + cosθ = 5/2, where 0 ≤ θ ≤ 90°, then what is…

Let cosα + cosβ = 2 and sinα + sinβ = 0, where 0 ≤…

Let ABC be a triangle right angled at C, then what is tan A +…