Question

does the equation $x - y^2 = 144$ define $y$ as a function of $x$?
\bigcirc yes
\bigcirc no
question help: \video \message instructor

Explanation:

Step1: Rearrange for $y$

$x - y^2 = 144 \implies y^2 = x - 144$

Step2: Solve for $y$

$y = \pm\sqrt{x - 144}$

Step3: Check function definition

A function requires one $y$ per $x$. Here, for $x>144$, there are two distinct $y$-values (positive and negative square roots).

Answer:

no