Answer:
3.34166666666666
Step-by-step explanation:
The volume of a cone is

where r = radius and h = height. If the cone has a volume of 94.2 cm³ (I assume you didn't mean m³ because that would be ridiculously huge) and a height of 10 cm, we can plug these values into the formula to find the radius. Don't do any rounding.

Now we know that's going to be the radius of our <em>new </em>cone as well since we're keeping the diameter the same. The volume is going to be double 94.2 which is 188.4. Let's solve for the height.
To find the zeros of this function, we must first set the entire function equal to 0
f(x) = x² - 2x - 15 = 0
Since this is a quadratic function, we must use the quadratic formula, which is:

Let's assign a, b, and c using our first function
x² means a = 1 (because it could be written as 1x²)
-2x means b = -2
-15 means c = -15
Now let's plug those in:

which simplifies to:

Simplified further:


And divide it by the 2 on the bottom gives us:

2+4 = 6
2-4 = -2
So the zeros of this function are
-2 and
6