The middle point of BC is (0,2), the midpoint of CD is (1,0)
to prove two lines are parallel, prove their slopes are the same.
slope of BD: m=rise/run=4/-2=-2 (the run is negative because to get to B from D on the grid, you have to move from right to left, then upward. If the horizontal move is from left to right, the run is positive)
slope of EG: m=rise/run=2/-1=-2
EG and BD have the same slope, so they are parallel.
How To Find Inverses:
1. First, replace f(x) with y . ...
2. Replace every x with a y and replace every y with an x .
3. Solve the equation from Step 2 for y . ...
4. Replace y with f−1(x) f − 1 ( x ) . ...
5. Verify your work by checking that (f∘f−1)(x)=x ( f ∘ f − 1 ) ( x ) = x and (f−1∘f)(x)=x ( f − 1 ∘ f ) ( x ) = x are both true.
The answer is
date
1 2 3 4 5 31
r1 r2 r3 r4 r5 . . . r31
1gm 2gms 3<span>gms 4gms 5gms . . . 31gms
r1+r2+ .... +r31= 31(31+1) /2=496gms (31 rings)
he only made 5 rings
31 rings----------> 496 gms
5 rings ------------> ? = 5 x496 / 31=80 gms
</span><span> the weights of those 5 rings was 80 gms</span>
Check the picture below.
something worth noticing 
so, we're really graphing x+2, with a hole at x = 3, however, when x = 3, we know that f(x) = 5, but but but, when x = 3, x+2 = 5, so we end up with a continuous line all the way, x ∈ ℝ, because the "hole" from the first subfunction, gets closed off by the second subfunction in the piece-wise.
