Tolong yang di buletin dong

14) Bayangan y = 3x - 5 oleh T1 = matriks dan dilanjutkan T2 = rotasi [0, -90°] adalah : (T2 o T1)(x, y) = (x', y')
(cos -90° ... - sin -90°) (2 ... 3) (x) = (x')
(sin -90° ..... cos -90°) (1 .... 2) (y) ... (y')

(0 ... 1) (2 .. 3) (x) = (x')
(-1 .. 0) (1 .. 2) (y) ... (y')

(1 ...... 2) (x) = (x')
(-2 .. -3) (y) ... (y')

(x) = 1/(-3 - (-4)) (-3 ... -2) (x')
(y) ...................... (2 ..... 1) (y')

(x) = (-3x' - 2y')
(y) .. (2x' + y')

Jadi bayangan dari y = 3x - 5 adalah
(2x' + y') = 3(-3x' - 2y') - 5
2x' + y' = -9x' - 6y' - 5
11x' + 7y' + 5 = 0

15) luas bayangan segitiga = luas segitiga awal . Det T
= 1/2 |A B C A| . |4 ..... 1|
............................. |-2 .. 2|

= 1/2 |1 .. 5 ... 1 ... 1| (4.2 - 1(-2))
......... |4 .. 1 ... 1 ...4|

= 1/2 |(1.1 + 5.1 + 1.4) - (5.4 + 1.1 + 1.1)| (8 + 2)
= 1/2 |(1 + 5 + 4) - (20 + 1 + 1)| (10)
= 1/2 |10 - 22| (10)
= 1/2 |-12| (10)
= 1/2 . 12 . 10
= 60