The temperature distribution in case of fin insulated at the tip is given by

• A. t – t₀/t₀ – t a = cos h m (3 – x)/cos ml
• B. t – t₀/t₀ – t a = cos h m (2 – x)/sin h ml
• C. t – t₀/t₀ – t a = cos h m (l – x)/cos h ml
• D. t – t₀/t₀ – t a = cos m (l – x)/sin ml