Solve for q.

k=4pq^2

K=4pq^2

k/4p=q^2

q = (k/4p) ^2

Solve for q:

k = 4 p q^2

k = 4 p q^2 is equivalent to 4 p q^2 = k:

4 p q^2 = k

Divide both sides by 4 p:

q^2 = k / (4 p)

Take the square root of both sides:

Answer: q = sqrt (k/p) / 2 or q = - sqrt (k/p) / 2