Question 938113

same, {{{sin^4 (theta)-cos^4 (theta)}}} is equal to {{{1/4}}} too

proof:

{{{sin^4 (theta)-cos^4 (theta) =(sin^2(theta)-cos^2(theta))(sin^2(theta)+cos^2(theta))}}}

{{{sin^4 (theta)-cos^4 (theta) =(1/4)(sin^2(theta)+cos^2(theta)) }}}

since  {{{sin^2(theta)+cos^2(theta)=1}}}


{{{sin^4 (theta)-cos^4 (theta )=1/4}}}