tolong jawab pertanyaan beserta cara

1.) √x²-1 = (x²-1)^½
½(x²-1)^½-1 * 2x
2x / 2(√x²-1)
x / √x²-1

2.) f(x) = 2x⁴ + x³ - 6x² + x
f'(x) = 8x³ + 3x² - 12x + 1
f'(-1) = 8(-1)³ + 3(-1)² - 12(-1) + 1
f'(-1) = -8 + 3 +12 + 1
= 16-8
= 8