Y-5=-1/2(X-2)
the simplified version of this equation (so you can plug into a calculator) is
Y=-1/2x+6
We can expand the logarithm of a product as a sum of logarithms:

Then using the change of base formula, we can derive the relationship

This immediately tells us that

Notice that none of
can be equal to 1. This is because

for any choice of
. This means we can safely do the following without worrying about division by 0.

so that

Similarly,

so that

So we end up with

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Another way to do this:



Then

So we have

Concave up is U-shaped.
There will be a inflection/critical point f'(x) =0 then a negative slope f'(x) = neg then another inflection/critical point f'(x) =0 at the bottom of the U-shape then a positive slope to last inflection/critical point. The interval for the Concave Up shape is the first and last inflection points.
Y = -1
It is an isosceles trapezoid, which is just as well, otherwise it could not reflect onto itself. The line of reflection is the same as the mirror line which is the same as the axis of symmetry.
It runs horizontally exactly through the middle of the shape.
All horizontal lines have the equation y = a value
In this case the line is <span>y=−<span>1</span></span>