The gradient of a curve is 2x + 7 and the curve passes through point (2, 0). find the equation of the curve.
- y = x2 + 7x + 9
-
y = x2 + 7x - 18
- y = x2 + 7x + 18
- y = x2 + 14x + 11
The correct answer is: B
Explanation
dy/dx = 2x + 7y = ∫2x + 7
y = x2 + 7x + C at (2,0)
0 = 22 + 7(2) + C
0 = 4 + 14 + C
0 = 18 + C
C = -18
∴ The equation is y = x2 + 7x - 18