Question

Help, please! I thought I knew what do but I don't; solve for x. I got 216.2.... but I'm pretty sure I'm wrong...

Answer 1

Use Pythagorean theorem:

`a^2+b^2=c^2`

We have

a = 3959 mi

b = x

c = 3959 mi + 5.9 mi = 3964.9 mi

Substitute:

`3959^2+x^2=3964.9^2\qquad\text{subtract}\ 3959^2\ \text{from both sides}\\\\x^2=3964.9^2-3959^2\qquad\text{use}\ a^2-b^2=(a-b)(a+b)\\\\x^2=(3964.9-3959)(3964.9+3959)\\\\x^2=(5.9)(7923.9)\\\\x^2=46751.01\to x=√(46751.01)\\\\x\approx216.2`

Answer: 216.2 mi.