7-3-85 integrating a constant to a variable
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Evaluate the following integral zero to two of two to the
negative Theta D Theta.
One way to do this, and there are lots of ways to do it, but
one way to do it is to replace 2 to the negative Theta is ELN 2
to the negative Theta.
Then bringing out the negative Theta in front as a coefficient
would get zero to two of E to the negative Theta LN2D Theta.
Now if we did AU substitution, we'd have U equaling negative
Theta LN2, IE the exponent.
So DU would equal negative LN2D Theta.
Remember, LN2 is a constant.
If I divide each side by that negative LN2, I'd get -1 divided
by LN2DU equaling D Theta.
Now going back to the original, we're going to take out the D
Theta and we're going to replace it with -1 over LN2DU.
And then the E is now going to be to EU because our U was that
negative Theta L and two.
We need to change our bounds.
So if we want to figure out what U of 0 is, we have -0 * l and
two, which is 0, and then we're going to put in U of two, so -2
L and two.
So now we get a new integral of -1 / l and two from zero to -2 L
and two E to the UDU.
And we know that E to the UDU, the integral is just E to EU.
So now we stick in our upper bound minus our lower bound E to
the -2 L and two.
I can take that -2 back up into the exponent and I get E to the
lane of two to the -2, which is just a fourth.
Any E to the zero, anything to the zero power is one other than
0 to the zero.
So if I have 1/4 -, 1, that gives me a negative 3/4.
If I multiply -3 fourths times the -1 over lane two, we can see
that that's 3 / 4 lane 2.