Risposta:
# 9 = 4r ^ 2cos ^ 2 (theta) -4r ^ 2sinthetacostheta + r ^ 2sin ^ 2 (theta) -5rsintheta + 3rcostheta = r (sintheta (r (sintheta-4costheta) -5) + costheta (4rcostheta + 3)) #
Spiegazione:
# x = rcostheta #
# Y = rsintheta #
# 9 = (- 2 (rcostheta) + rsintheta) ^ 2-5rsintheta + 3rcostheta #
# 9 = 4r ^ 2cos ^ 2 (theta) -4r ^ 2sinthetacostheta + r ^ 2sin ^ 2 (theta) -5rsintheta + 3rcostheta #
# 9 = r (sintheta (r (sintheta-4costheta) -5) + costheta (4rcostheta + 3)) #