Kako pretvorite 2y = y ^ 2-x ^ 2 -4x v polarno enačbo?

Kako pretvorite 2y = y ^ 2-x ^ 2 -4x v polarno enačbo?
Anonim

Odgovor:

#r = - ((2sin (theta) + 4cos (theta)) / cos (2theta)) #

Pojasnilo:

# 2y = y ^ 2-x ^ 2-4x #

# x = rcos (theta) #

# y = rsin (theta) #

Te vrednosti vključite v dano enačbo

# 2rsin (theta) = r ^ 2sin ^ 2 (theta) -r ^ 2cos ^ 2 (theta) -4rcos (theta) #

# 2rsin (theta) + 4rcos (theta) = - r ^ 2 (cos ^ 2 (theta) -sin ^ 2 (theta)) #

#r (2sin (theta) + 4cos (theta)) = - r ^ 2 (cos (2theta)) #

Uporabil je identiteto #cos (2theta) = cos ^ 2 (theta) -sin ^ 2 (theta) #

#r = - ((2sin (theta) + 4cos (theta)) / cos (2theta)) #