Final answer:
To eliminate the parameter in parametric equations, we solve for x and y in terms of the parameter. The curve is described by the equation y = ax + bx^2, where the signs of a and b determine the orientation.
Step-by-step explanation:
To eliminate the parameter and obtain an equation in x and y, we can equate the two given parametric equations:
x = a + bt
y = c + dt
We can solve the first equation for a:
a = x - bt
Substituting the value of a into the second equation:
y = c + d(x - bt)
Expanding and rearranging terms:
y = c + dx - bdt
y = (c - bdt) + dx
So, the equation in x and y is y = (c - bdt) + dx.
For part b, the curve described by the equation will depend on the values of b, d, and c. If b > 0, the curve will slope upward to the right. If b = 0, the curve will be horizontal. If b < 0, the curve will slope downward to the right. The positive orientation of the curve will depend on the values of d and c in relation to the slope.