How to show that 1+tan²(θ)=sec²(θ) and 1+cot²(θ)=cosec²(θ) Get link Facebook X Pinterest Email Other Apps September 02, 2021 In the workings below I demonstrate how you can derive 1+tan²(θ)=sec²(θ) and 1+cot²(θ)=cosec²(θ) using sin²(θ)+cos²(θ)=1 . Just follow the instructions, and presto! Read more