Definite Integration - By Formulae
Definite Integration - By Formulae
Last updated at August 18, 2026 by Teachoo
Transcript
Ex 7.8, 12 ∫_0^(𝜋/2)▒〖𝑐𝑜𝑠2 𝑥 𝑑𝑥〗 Step 1 :- Let F(𝑥)=∫1▒〖𝑐𝑜𝑠^2 𝑥 𝑑𝑥〗 = ∫1▒(cos2𝑥 + 1)/2 𝑑𝑥 =1/2 ∫1▒〖𝑐𝑜𝑠 2𝑥 𝑑𝑥+1/2 ∫1▒𝑑𝑥〗 =1/2 × (𝑠𝑖𝑛 2𝑥)/2+𝑥/2 =1/4 𝑠𝑖𝑛 2𝑥+ 𝑥/2 Hence , F(𝑥)=1/4 𝑠𝑖𝑛 2𝑥+ 𝑥/2 Step 2 :- ∫_0^(𝜋/2)▒〖𝑐𝑜𝑠^2 𝑥=𝐹(𝜋/2)−𝐹(0) 〗 =1/4 𝑠𝑖𝑛(2 ×𝜋/2)+((𝜋/2))/2−1/4 𝑠𝑖𝑛(2×0/2)−0/2 =1/4 𝑠𝑖𝑛(𝜋)+𝜋/4−1/4 〖 sin〗〖0 −0〗 =1/4 ×0+ 𝜋/4− 1/4 ×0−0 = 𝝅/𝟒