一道高一的数学题 过程要求！

(cosπ/8+sinπ/8)*(cosπ/8-sinπ/8)(sinπ/8平方+cosπ/8平方+sinπ/8*cosπ/8)
=（cosπ/8平方-sinπ/8平方）*（1+0.5*sinπ/4）
=cos（π/4）*（1+根号2/4）
=根号2/2*（1+根号2/4）

(cosπ/8+sinπ/8)(cos立方π/8-sin立方π/8)
=(cosπ/8+sinπ/8)(cosπ/8-sinπ/8)(cos平方π/8+cosπ/8sinπ/8+sin平方π/8)
=(cos平方π/8-sin平方π/8)(1+cosπ/8sinπ/8)
=cosπ/4[1+(sinπ/4)/2]
=√2/2(1+√2/4)
=√2/2+1/4

(cosπ/8+sinπ/8)(cos立方π/8-sin立方π/8)
=(cosπ/8+sinπ/8)(cosπ/8-sinπ/8)(cos平方π/8+cosπ/8*sinπ/8+sin平方π/8)
=[(cosπ/8+sinπ/8)(cosπ/8-sinπ/8)](cos平方π/8+sin平方π/8+cosπ/8*sinπ/8)
=（cos平方π/8-sin平方π/8）*（1+cosπ/8*sinπ/8）
=cosπ/4*（1+(sinπ/4)/2）
=cosπ/4+cosπ/4*(sinπ/4)/2
=cosπ/4+(sinπ/2)/4
=二分之根号二+四分之一