00:01
Today we are going to be finding the equation of a line that is tangent to the curve 2x plus 1 over x plus 2 at the point 1.
00:07
To find the slope of this line, we'll use the equation the limit as x approaches a of f of f of a all over x minus a, and in our case, a is equal to 1.
00:18
So plugging into the equation, the limit as x approaches 1 of 2x plus 1 over x plus 2 minus 2 times 1, plus 1 over 1 plus 2, all divided by x minus 1.
00:36
We'll simplify this a little bit.
00:39
We get the limit of x approaches 1 of 2x plus 1 over x plus 2 minus 1, all divided by x minus 1.
00:51
We multiply by the reciprocal to get the limit of x as x approaches 1 of 2x plus 1 over x plus 2 minus 1.
01:00
And all of that times 1 over x minus 1.
01:06
And to multiply that out, we get the limit of as x approaches 1 of 2x plus 1 over x plus 2 times x minus 1, minus 1, minus 1 over x minus 1.
01:21
To combine that all in 1 fraction, we have the limit as x approaches 1 of 2x plus 1 minus x plus 2, all over x plus 2 times x minus 1...