Garett is attempting to verify this trig identity. He makes a mistake on one of the lines below. Which line has his first mistake?
sec(θ)−sin(θ)tan(θ)=cos(θ)
1.1cos(θ)−sin(θ)1(sin(θ)cos(θ))=cos(θ)
2. 1cos(θ)−sin(θ)cos(θ)=cos(θ)
3. 1−sin(θ)cos(θ)=cos(θ)
4. cos(θ)=cos(θ)