sederhanakan bentuk operasi berikut : (sinx + cosx ) kuadrat + (sinx - cosx) kuadrat

(y/r + x/r)^2 + (y/r - x/r)^2
r/r^2 + -r/r^2
0

(sinx + cosx)² + (sinx - cosx)²

= (sinx + cosx)(sinx + cosx) + (sinx - cosx)(sinx - cosx)

= sin²x + 2sinxcosx + cos²x + sin²x - 2sinxcosx + cos²x

= sin²x + sin²x + cos²x + cos²x

= 2sin²x + 2cos²x

= 2 (sin²x + cos²x)

= 2 (1)

= 2