Kako pretvorite y = -y ^ 2-3x ^ 2-xy v polarno enačbo?

Kako pretvorite y = -y ^ 2-3x ^ 2-xy v polarno enačbo?
Anonim

Odgovor:

#r = - (sintheta) / (sin ^ 2theta + 3cos ^ 2theta + costhetasintheta) #

Pojasnilo:

Ponovno napišite kot:

# y ^ 2 + 3x ^ 2 + xy = -y #

Nadomestiti v:

# x = rcostheta #

# y = rsintheta #

# (rsintheta) ^ 2 + 3 (rcostheta) ^ 2 + (rcostheta) (rsintheta) = - rsintheta #

# r ^ 2 (sintheta) ^ 2 + 3r ^ 2 (costheta) ^ 2 + r ^ 2 (costhetasintheta) = - rsintheta #

Razdelite obe strani z # r #

#r (sintheta) ^ 2 + 3r (costheta) ^ 2 + r (costhetasintheta) = - sintheta #

Faktorizirajte # r #:

#r (sin ^ 2theta + 3cos ^ 2theta + costhetasintheta) = - sintheta #

Znamka # r # predmet:

#r = - (sintheta) / (sin ^ 2theta + 3cos ^ 2theta + costhetasintheta) #