bayangan tirik P(8,-10)pd rotasi -90 derajat dgn pusat O adl...tlng jwb pk cara yaa..tks

x' = x cos (-90)- y sin (-90)
x' = 8 (0) +10 (-1)
x' = -10

y' = x sin(-90) + y cos (-90)
y' = 8 (-1) - 10 (0)
y' = -8

P'( -10,-8)