Aká je rovnica kruhu so stredom na (7, 1) a polomerom 2?

odpoveď:

#y = + - # # Sqrt (4- (x²-14x + 49)) + 1 #.

vysvetlenie:

Pre kruh so stredom # (H, K), # a polomer # R #:

# (x-h) ^ 2 + (y-k) ^ 2 = r ^ 2 #.

tak

# (x-7) ^ 2 + (y-1) ^ 2 = 4 #

# x ^ 2-14x + 49 + y ^ 2-2y + 1 = 4 #

# (y-1) ^ 2 = 4- (x ^ 2-14x + 49) #

# (y-1) = sq {4- (x ^ 2-14x + 49)} #

graf {(x-7) ^ 2 + (y-1) ^ 2 = 4 -1,42, 11,064, -2,296, 3,944}