Question

18-

Eliminate the parameter.

x = t + 4, y = t2

Answer Choices:
A) y = square root of x + x + 4
B) y = square root of quantity x minus four
C) y = x2 + 16
D) y = x2 - 8x + 16

Answer 1

x = t +4
y = t^2

Rewrite the first equation:

x = t+4
Subtract 4 from each side:
t = x-4

Replace t in the 2nd equation with the rewritten equation:

y = x-4^2

Rewrite x-4^2 as (x-4)(x-4)

Use FOIL to get y = x^2-8x+16

The answer is D.