Bantu matematika Komposisi Transformasi no 5 kelas 11

jawab

(x', y' ) = (x , y) + (a, 2)  + (-2 ,b)
maka
x' = x + a - 2 → x = x' +2 - a ..(i)
y' = y+ 2 + b → y = y' - 2 - b..(ii)
substitusikan ke  y = 3x² + 6x + 7
y' - 2 - b = 3(x' + 2 - a)² + 6(x' + 2 - a) + 7
y' - 2 - b = 3(x'²+ 2ax -4x -4a + 4 + a²) + 6x'+12-6a + 7
y= 2 +b+ 3x²+6ax- 12x-12a+12+3a² +6x +12-6a + 7
y = 3x²+ x(6a-12+6) + (3a²-18a+33+b)
y = 3x² + x(6a-6) +(3a²-18a+33+b)
y = 3x² - 24 x + 52

6a - 6 = - 24
6a = -18
a= - 3

3a² -18a + 33 + b = 52
3(9) - 18(-3)+ 31 + b = 52
112 + b = 52
b = -60

a- b = - 3 - (-60)
a -b = 57