Question

Jika f(x) =3-2x+x^2, nilai f(x+t)-f(x)per t adalah

Answer 1

F(x+t) = 3 - 2(x+t) + (x+t)²
f(x+t) = 3 - 2x - 2t + x² + 2t x + t²
f(x+t)= x² - 2x + 3 + t² + 2tx - 2t

(f(x+t)  - f(x)) / (t) = 
= (x²  - 2x  + 3 +t²+2 tx - 2t) - (3 - 2x + x²) / (t)
= (x²- x² - 2x + 2x + 3 - 3 + t² + 2 tx - 2t)/(t)
= t² + 2tx - 2t / (t)
= t(t + 2x - 2)/(t)
= t + 2x  - 2