A hint to get started
Apply the double-angle formula twice
Using , show that . Hence find .
CJC · Lecture · Example 13
Use double angle first for cos squared x, then for cos squared 2x, as the source callouts specify.
Read the worked solution
A hint to get started
Using cos2A=2cos2A−1, show that cos4x=83+21cos2x+81cos4x. Hence find ∫cos4xdx.
CJC · Lecture · Example 13
Use double angle first for cos squared x, then for cos squared 2x, as the source callouts specify.