The radius of the event horizon of a black hole (the point at which it is impossible to escape the black hole because the escape velocity would exceed the speed of light) is given by the formula r = 2Gm/c^2, where G is the gravitational constant, c is the speed of light, and m is the mass of the black hole.

Rearrange this formula to isolate c.

r= 2Gm/c^2

rc^2=2Gm

c^2=(2Gm)/r

c=+or- sqrt[(2Gm)/r]

c= sqrt[(2Gm)/r] (the speed of light is positive)

r = 2Gm/c^2

c^2 = 2Gm/r
now just take the square root.

To isolate c in the formula r = 2Gm/c^2, we can follow these steps:

1. Start with the given formula: r = 2Gm/c^2

2. Multiply both sides of the equation by c^2: r * c^2 = 2Gm

3. Divide both sides of the equation by r: c^2 = 2Gm/r

4. Take the square root of both sides to solve for c: √(c^2) = √(2Gm/r)

5. Simplify the left side of the equation: c = √(2Gm/r)

Therefore, the rearranged formula to isolate c is: c = √(2Gm/r).

To rearrange the formula r = 2Gm/c^2 to isolate c, we can follow these steps:

Step 1: Multiply both sides of the equation by c^2 to eliminate the denominator on the right side:
r * c^2 = 2Gm

Step 2: Divide both sides of the equation by r to isolate c^2:
c^2 = (2Gm) / r

Step 3: Take the square root of both sides to solve for c:
c = √[(2Gm) / r]

Thus, the formula to isolate c is c = √[(2Gm) / r].