Question

Energy required to change orientation magnetic pole

Answer 1

In the above slide, it reads that W=∫μBsin(θ)dθ=μBcos(θ)W=∫μBsin(θ)dθ=μBcos(θ).

But, I thought that ∫μBsin(θ)dθ=−μBcos(θ)∫μBsin(θ)dθ=−μBcos(θ)by some calculus calculation.