Turunan pertama fungsi f(x) = √2x – 5
adalah
f'(x) = 1/√2x – 5
Pembahasan:
f(x) = √2x – 5 = (2x – 5)½
Misalkan u(x) = 2x – 5 maka u'(x) = 2
f(x) = (u(x)ⁿ ⇔ f'(x) = n(u(x))ⁿ⁻¹ × u'(x)
f'(x) = ½(u(x))½⁻¹ × u'(x)
= ½(2x – 5)⁻½ × 2
= (2x – 5)⁻½
= 1
√2x – 5