JAMB - Mathematics (2021 - No. 30)
If g(x) = x\(^2\) + 3x find g(x + 1) - g(x)
(x + 2)
2(x + 2)
(2x + 1)
(x2 + 4)
स्पष्टीकरण
g(x) = x2 + 3x
When g(x + 1) = (x + 1)^2 + 3(x + 1)
= x\(^2\) + 1 + 2x + 3x + 3
= x\(^2\) + 5x + 4
g(x + 1) - g(x) = x2 + 5x + 8 - (x\(^2\) + 3x)
= x\(^2\) + 5x + 4 - x2 -3x
= 2x + 4 or 2(x + 4)
= 2(x + 2)
When g(x + 1) = (x + 1)^2 + 3(x + 1)
= x\(^2\) + 1 + 2x + 3x + 3
= x\(^2\) + 5x + 4
g(x + 1) - g(x) = x2 + 5x + 8 - (x\(^2\) + 3x)
= x\(^2\) + 5x + 4 - x2 -3x
= 2x + 4 or 2(x + 4)
= 2(x + 2)