Solve 19cos θ = 5 cos θ + 14 for all values of θ if θ is measured in radians.

Ф=xπ, x={0,+∞}

Step-by-step explanation:

be 19cosФ=5cosФ+14 → 19cosФ-5cosФ-14 → 14cosФ-14=0 → cosФ=1

then, values for which cosФ=1 are Ф=0º=360º=720º ..., but the values of Ф must be radians, so Ф=xπ, where x∈Z, not including the negative numbers,

x={0,1,2,3, ... ∞}

Note: π≅3.141592

when calculating the values, it must be done in radian mode