Math(Please help)
posted by Abbey .
2) Use the sum and difference identites
sin[x + pi/4] + sin[xpi/4] = 1
sinx cospi/4 + cosxsin pi/4 + sinx cos pi/4  cosx sin pi/4 = 1
2 sin x cos pi/4 =1
cos pi/4 = sqr2/2
2sin^x(sqrt2/2) = 1
sin x = sqrt2
x = 7pi/4 and 5pi/4
Am I correct?

2sin^x(sqrt2/2) = 1
sin x = 1/sqrt2 =  sqrt 2 /2
x = pi + pi/4 = 5 pi/4
x = 2 pi  pi/4 = 7 pi /4
so I agree with you but you seem to have a typo