Question

Please help it is an emergency,,,,, points and metal reward

Eliminate the parameter of:

x = 4 cos t, y = 4 sin t

Answer 1

Recall the Pythagorean identity:

$\cos^2x+\sin^2x=1$

so

$x^2+y^2=(4\cos t)^2+(4\sin t)^2=16(\cos^2t+\sin^2t)=16$