Maths problem: how to do, thanks?

2sin^2(22°)+2sin^2(68°)
    = 2[sih^2(22°)+sin^2(90°-22°)]
    = 2[sin^2(22°)+cos^2(22°)]       (∵ sin(90°-x) = cos(x).)
    = 2         (∵ sin^2(x) + cos^2(x) = 1)