y=sin(x+pi)sin(x-pi)

Solution for y=sin(x+pi)sin(x-pi) equation:

Simplifying
y = sin(x + pi) * sin(x + -1pi)

Reorder the terms:
y = ins(ip + x) * sin(x + -1pi)

Reorder the terms:
y = ins(ip + x) * ins(-1ip + x)

Reorder the terms for easier multiplication:
y = ins * ins(ip + x)(-1ip + x)

Multiply ins * ins
y = i2n2s2(ip + x)(-1ip + x)

Multiply (ip + x) * (-1ip + x)
y = i2n2s2(ip(-1ip + x) + x(-1ip + x))
y = i2n2s2((-1ip * ip + x * ip) + x(-1ip + x))

Reorder the terms:
y = i2n2s2((ipx + -1i2p2) + x(-1ip + x))
y = i2n2s2((ipx + -1i2p2) + x(-1ip + x))
y = i2n2s2(ipx + -1i2p2 + (-1ip * x + x * x))
y = i2n2s2(ipx + -1i2p2 + (-1ipx + x2))

Reorder the terms:
y = i2n2s2(ipx + -1ipx + -1i2p2 + x2)

Combine like terms: ipx + -1ipx = 0
y = i2n2s2(0 + -1i2p2 + x2)
y = i2n2s2(-1i2p2 + x2)
y = (-1i2p2 * i2n2s2 + x2 * i2n2s2)

Reorder the terms:
y = (i2n2s2x2 + -1i4n2p2s2)
y = (i2n2s2x2 + -1i4n2p2s2)

Solving
y = i2n2s2x2 + -1i4n2p2s2

Solving for variable 'y'.

Move all terms containing y to the left, all other terms to the right.

Simplifying
y = i2n2s2x2 + -1i4n2p2s2