Answer:
<h2>
301.593</h2><h2 />
Step-by-step explanation:
surface area = 2πrh + 2πr²
where r = 4 km radius
h = 8 km
<u>plugin values into the formula</u>
surface area = 2πrh + 2πr²
= 2π (4) 8 + 2π (4)²
= 201.062 + 100.531
= 301.593 km²
I know of two ways to solve quadratic equations. The first is through factoring. Let us take the example (x^2)+2x+1=0. We can factor this equation out and the factors would be (x+1)(x+1)=0. To solve for the roots, we equate each factor to 0, that is
x+1=0; x+1=0
In this case, the factors are the same so the root of the equation is
x=1.
The other way is to use the quadratic formula. The quadratic formula is given as [-b(+-)sqrt(b^2-4ac)]/2a where, using our sample equation above, a=1, b=2 and c=1. Substitute these to the formula, and you will get the same answer as the method above.