cos(x+y) x cos(x-y) = cos squared y - sin squared x
= cos squared x - sin squared y
used double angle formulae except seemed to only get up to
cossquaredx cossquared y - sin squared x sin squared y ??
any help is GREATLY APPRECIATED
thankss !!
cos(x+y) x cos(x-y) = cos squared y - sin squared x
= cos squared x - sin squared y
used double angle formulae except seemed to only get up to
cossquaredx cossquared y - sin squared x sin squared y ??
any help is GREATLY APPRECIATED
thankss !!